fix(alarms): re-assert non-normal scripted-alarm conditions after a (re)load (#487)

A deploy that triggers a FULL address-space rebuild clears `_alarmConditions`
and re-materialises every condition node fresh — inactive, acked, confirmed,
unshelved. The engine reloads its persisted state and re-derives Active from the
predicate, so it ends up correct; but there is no transition to report, so
`LoadAsync` yields `EmissionKind.None` and `OnEngineEmission` drops it. Nothing
writes the node.

Live-reproduced on the docker-dev rig against the pre-fix image: an alarm that
had fired and cleared but was still UNACKNOWLEDGED came back from a rebuild
reporting Acknowledged with Retain=false — so it disappeared from
ConditionRefresh entirely, while the engine still held Unacknowledged. An
operator's outstanding alarm silently vanishes from the alarm list on deploy.

`ScriptedAlarmHostActor.ReassertConditionNodes` closes it. After each load it
reads the new `ScriptedAlarmEngine.GetProjections()` and sends one
`AlarmStateUpdate` per alarm NOT in the Part 9 no-event position.

Load-bearing properties:

- Node-only. It sends `AlarmStateUpdate` and nothing else — never the `alerts`
  topic, never the telemetry hub. `alerts` is the historization path, so a row
  per alarm per deploy would append a duplicate historian/AVEVA record every
  time anyone deploys. This is why it reads a projection rather than re-emitting:
  `ScriptedAlarmProjection` carries no `EmissionKind`, so there is nothing for
  the emission machinery — or a future refactor — to mistake for a transition.
  The issue's sketch said `GetState(alarmId)` + `LoadedAlarmIds`; that alone
  would have clobbered the node's severity and message, so the projection also
  carries the definition's severity, the resolved message template, and the
  last-observed worst-input quality.
- Only non-normal alarms. One in the no-event position already matches what the
  materialise built, so a never-fired alarm stays byte-identical to a deploy
  without this pass (including its Message, which the materialise seeds with the
  display name), and an all-normal deploy writes nothing at all.
- Timestamp is the condition's own `LastTransitionUtc`, not the deploy instant.
- No duplicate Part 9 events: `WriteAlarmCondition`'s delta-gate compares against
  the node's CURRENT state, so a re-assert onto a freshly materialised node is a
  genuine delta (fires once — correct, the rebuild reset what clients see) while
  one onto a surgically-preserved node is suppressed.

Tests: 6 new host tests + 6 new engine tests. Falsifiability checked by
disabling the call — 4 of the 6 host tests go red; the other 2 are absence
guards against an over-broad fix and pass either way by design.

Live gate (docker-dev, central-2, pre-fix image vs. rebuilt image):
- pre-fix: condition absent from ConditionRefresh after a rebuild;
- post-fix: present, Unacknowledged, Retain=True, stamped with its own
  LastTransitionUtc rather than the restart instant;
- /alerts stayed empty across two re-asserts, with the panel proven live by a
  real ACTIVATED transition immediately afterwards — no duplicate history.

Directory.Packages.props

@@ -77,6 +77,10 @@
     <PackageVersion Include="Moq" Version="4.20.72" />
     <PackageVersion Include="Novell.Directory.Ldap.NETStandard" Version="3.6.0" />
     <PackageVersion Include="OPCFoundation.NetStandard.Opc.Ua.Client" Version="1.5.378.106" />
+    <!-- Core carries Opc.Ua.StatusCodes, the oracle StatusCodeParityTests checks the drivers'
+         hard-coded uint constants against. Referenced by that TEST project only — the drivers
+         themselves stay SDK-free by design and keep spelling status codes as bare uints. -->
+    <PackageVersion Include="OPCFoundation.NetStandard.Opc.Ua.Core" Version="1.5.378.106" />
     <PackageVersion Include="OPCFoundation.NetStandard.Opc.Ua.Configuration" Version="1.5.378.106" />
     <PackageVersion Include="OPCFoundation.NetStandard.Opc.Ua.Server" Version="1.5.378.106" />
     <!-- OpenTelemetry.Api < 1.15.3 has GHSA-g94r-2vxg-569j (header-parsing memory DoS). The trio

docker-dev/docker-compose.yml

@@ -272,6 +272,12 @@ services:
       OTOPCUA_ROLES: "admin,driver,cluster-MAIN"
       ASPNETCORE_URLS: "http://+:9000"
       ConnectionStrings__ConfigDb: "Server=sql,1433;Database=OtOpcUa;User Id=sa;Password=OtOpcUa!Dev123;TrustServerCertificate=True;"
+      # Sql poll driver — the named connection string a Sql driver instance references by
+      # `connectionStringRef: "DevSql"`. Resolved in-process by SqlConnectionStringResolver (driver
+      # node) and SqlDriverBrowser (AdminUI browse), env-only, never persisted to ConfigDb. Points at
+      # the rig's own `sql` container, a SEPARATE `DevSql` database seeded with dbo.TagValues (KeyValue)
+      # + dbo.LatestStatus (WideRow). Committed-dev-secret exception, same as ConfigDb above.
+      Sql__ConnectionStrings__DevSql: "Server=sql,1433;Database=DevSql;User Id=sa;Password=OtOpcUa!Dev123;TrustServerCertificate=True;"
       Cluster__Hostname: "0.0.0.0"
       Cluster__Port: "4053"
       Cluster__PublicHostname: "central-1"
@@ -391,6 +397,12 @@ services:
       OTOPCUA_ROLES: "admin,driver,cluster-MAIN"
       ASPNETCORE_URLS: "http://+:9000"
       ConnectionStrings__ConfigDb: "Server=sql,1433;Database=OtOpcUa;User Id=sa;Password=OtOpcUa!Dev123;TrustServerCertificate=True;"
+      # Sql poll driver — the named connection string a Sql driver instance references by
+      # `connectionStringRef: "DevSql"`. Resolved in-process by SqlConnectionStringResolver (driver
+      # node) and SqlDriverBrowser (AdminUI browse), env-only, never persisted to ConfigDb. Points at
+      # the rig's own `sql` container, a SEPARATE `DevSql` database seeded with dbo.TagValues (KeyValue)
+      # + dbo.LatestStatus (WideRow). Committed-dev-secret exception, same as ConfigDb above.
+      Sql__ConnectionStrings__DevSql: "Server=sql,1433;Database=DevSql;User Id=sa;Password=OtOpcUa!Dev123;TrustServerCertificate=True;"
       Cluster__Hostname: "0.0.0.0"
       Cluster__Port: "4053"
       Cluster__PublicHostname: "central-2"

docs/ScriptedAlarms.md

@@ -102,6 +102,45 @@ Persisted scope per plan decision #14: `Enabled`, `Acked`, `Confirmed`, `Shelvin
 
 Every mutation the state machine produces is immediately persisted inside the engine's `_evalGate` semaphore, so the store's view is always consistent with the in-memory state.
 
+### Post-(re)load condition-node re-assert (#487)
+
+A deploy that triggers a **full address-space rebuild** clears `_alarmConditions` and re-materialises every
+condition node fresh — inactive, acked, confirmed, unshelved. The engine, reloading in parallel, restores each
+alarm's persisted state and re-derives `Active` from the predicate, so it ends up *correct*; but a still-active
+alarm has **no transition to report**, so `LoadAsync` yields `EmissionKind.None` and `OnEngineEmission` drops it.
+Nothing then writes the node. Before this fix, an active alarm with static dependencies read **normal** to every
+OPC UA client after such a deploy, until its next real transition — which for a static-dependency alarm may
+never come.
+
+`ScriptedAlarmHostActor.ReassertConditionNodes` closes it. After each load completes it reads
+`ScriptedAlarmEngine.GetProjections()` — a plain read returning `ScriptedAlarmProjection` (condition state +
+the definition's severity + the resolved message template + last-observed worst-input quality) — and sends one
+`OpcUaPublishActor.AlarmStateUpdate` per alarm that is **not** in the Part 9 no-event position.
+
+Four properties are load-bearing:
+
+- **Node-only.** It sends `AlarmStateUpdate` and nothing else — never the `alerts` topic, never the telemetry
+  hub. `alerts` is the historization path, so an alerts row per alarm per deploy would append a duplicate
+  historian / AVEVA record every time anyone deploys. This is why the re-assert reads a projection instead of
+  re-emitting: `ScriptedAlarmProjection` carries no `EmissionKind`, so there is nothing for the emission
+  machinery — or a future refactor — to mistake for a transition.
+- **Only non-normal alarms.** An alarm in the no-event position (enabled, inactive, acked, confirmed,
+  unshelved) already matches what the materialise built, so it is skipped. That keeps a never-fired alarm
+  byte-identical to a deploy without this pass — including its Message, which the materialise seeds with the
+  alarm's display name — and writes nothing at all on the common all-normal deploy.
+- **Ordering.** `DriverHostActor` tells `RebuildAddressSpace` to the publish actor *before* it tells
+  `ApplyScriptedAlarms` to the host, and the re-assert runs later still (after an awaited `LoadAsync` pipes
+  back). Both are local `Tell`s, which enqueue synchronously, so the re-materialise is already queued ahead of
+  these writes.
+- **No duplicate Part 9 events.** `WriteAlarmCondition`'s delta-gate compares the incoming snapshot against
+  the node's *current* state: a re-assert onto a freshly materialised (normal) node is a genuine delta and
+  fires exactly one condition event — correct, since the rebuild reset what clients see — while a re-assert
+  onto a surgically-preserved node that already holds the same state is suppressed. The write is ungated by
+  redundancy role, like every other node write here; the Secondary keeps its address space warm for failover.
+
+The timestamp carried is the condition's own `LastTransitionUtc`, **not** the deploy instant, so a client
+reading `Time` / `ReceiveTime` after a rebuild still sees when the alarm actually went active.
+
 ## Source integration
 
 `ScriptedAlarmSource` (`ScriptedAlarmSource.cs`) adapts the engine to the driver-agnostic `IAlarmSource` interface. The existing `AlarmSurfaceInvoker` + `GenericDriverNodeManager` fan-out consumes it the same way it consumes Galaxy / AB CIP / FOCAS sources — there is no scripted-alarm-specific code path in the server plumbing. From that point on, the flow into `AlarmConditionState` nodes, the `AlarmAck` session check, and the Historian sink is shared — see [AlarmTracking.md](AlarmTracking.md).

docs/plans/2026-06-26-otopcua-historian-gateway-integration.md

@@ -271,7 +271,7 @@ public sealed class GatewayQualityMapperTests
 {
     [Theory]
     [InlineData(192, 0x00000000u)] // Good
-    [InlineData(216, 0x00D80000u)] // Good_LocalOverride
+    [InlineData(216, 0x00960000u)] // Good_LocalOverride
     [InlineData(64,  0x40000000u)] // Uncertain
     [InlineData(0,   0x80000000u)] // Bad
     [InlineData(8,   0x808A0000u)] // Bad_NotConnected
@@ -307,7 +307,7 @@ public sealed class SampleMapperTests
     {
         var a = new HistorianAggregateSample { Tag = "T", /* Value unset */ EndTime = Ts(2026,1,1,0,0,0) };
         var snap = SampleMapper.ToAggregateSnapshot(a);
-        Assert.Equal(0x800E0000u, snap.StatusCode); // BadNoData
+        Assert.Equal(0x809B0000u, snap.StatusCode); // BadNoData
         Assert.Null(snap.Value);
     }
     // Ts(...) builds a Google.Protobuf.WellKnownTypes.Timestamp from UTC parts.
@@ -323,7 +323,7 @@ public sealed class SampleMapperTests
   - `StatusCode`: `GatewayQualityMapper.Map((byte)s.OpcQuality)` (prefer `opc_quality`; if zero/unset and `quality` carries the OPC-DA byte, fall back to `quality` — match whatever the gateway populates; document the choice).
   - `SourceTimestampUtc`: `s.Timestamp.ToDateTime()` (UTC kind).
   - `ServerTimestampUtc`: `DateTime.UtcNow`.
-- `SampleMapper.ToAggregateSnapshot(HistorianAggregateSample)` → null aggregate value ⇒ `StatusCode 0x800E0000` (BadNoData), non-null ⇒ Good (`0x00000000`) with the value; `SourceTimestampUtc` ← the bucket end/start timestamp (match the Wonderware `ToAggregateSnapshots` convention — it stamps the bucket timestamp). Provide `IReadOnlyList<>` batch helpers too.
+- `SampleMapper.ToAggregateSnapshot(HistorianAggregateSample)` → null aggregate value ⇒ `StatusCode 0x809B0000` (BadNoData), non-null ⇒ Good (`0x00000000`) with the value; `SourceTimestampUtc` ← the bucket end/start timestamp (match the Wonderware `ToAggregateSnapshots` convention — it stamps the bucket timestamp). Provide `IReadOnlyList<>` batch helpers too.
 
 **Step 4: run, expect PASS.**
 

docs/plans/2026-07-15-mtconnect-driver-design.md

@@ -98,7 +98,7 @@ Pure function in `.Contracts` (shared by driver, browser-commit, and the typed e
 | `EVENT` free text (`Program`, `Block`, `Message`) | `String` |
 | `CONDITION` | `String` (state word; §3.6) |
 
-**Quality mapping (`DataValueSnapshot.StatusCode`):** an observation value of `UNAVAILABLE` (MTConnect's explicit no-data sentinel) → **`BadNoCommunication` (`0x80310000u`)** with a null value, not the literal string — this is *the* UNAVAILABLE code, used everywhere in this design (read, subscribe, and the §8 fixtures). Rationale + fleet fit: semantically, `UNAVAILABLE` means the Agent is reachable but has no device-backed value (the adapter↔device link is down or the item has never reported) — exactly OPC UA's `BadNoCommunication` ("communication to the data source has failed"). The fleet grep shows no competing convention for this case: every existing driver's `BadCommunicationError` (`0x80050000u`, Modbus/FOCAS/TwinCAT/OpcUaClient/S7/AbCip/AbLegacy/Galaxy) marks the **driver's own transport failure** to its peer — a different failure (and the code this driver also uses when the *Agent* HTTP call fails, per §7) — while `BadNoData` (`0x800E0000u`) is historian-domain only (`Historian.Gateway/Mapping/SampleMapper.cs`). `BadNoCommunication` is already in the CLI's `SnapshotFormatter` name table (`src/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.Cli.Common/SnapshotFormatter.cs`), so it renders by name, not hex. Declare it as a `private const uint` in `MTConnectDriver` (the Modbus `StatusBadCommunicationError` pattern). Missing dataItem / empty condition → `Bad`. `observation.timestamp` → `SourceTimestamp` (not a separate node).
+**Quality mapping (`DataValueSnapshot.StatusCode`):** an observation value of `UNAVAILABLE` (MTConnect's explicit no-data sentinel) → **`BadNoCommunication` (`0x80310000u`)** with a null value, not the literal string — this is *the* UNAVAILABLE code, used everywhere in this design (read, subscribe, and the §8 fixtures). Rationale + fleet fit: semantically, `UNAVAILABLE` means the Agent is reachable but has no device-backed value (the adapter↔device link is down or the item has never reported) — exactly OPC UA's `BadNoCommunication` ("communication to the data source has failed"). The fleet grep shows no competing convention for this case: every existing driver's `BadCommunicationError` (`0x80050000u`, Modbus/FOCAS/TwinCAT/OpcUaClient/S7/AbCip/AbLegacy/Galaxy) marks the **driver's own transport failure** to its peer — a different failure (and the code this driver also uses when the *Agent* HTTP call fails, per §7) — while `BadNoData` (`0x809B0000u`) is historian-domain only (`Historian.Gateway/Mapping/SampleMapper.cs`). `BadNoCommunication` is already in the CLI's `SnapshotFormatter` name table (`src/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.Cli.Common/SnapshotFormatter.cs`), so it renders by name, not hex. Declare it as a `private const uint` in `MTConnectDriver` (the Modbus `StatusBadCommunicationError` pattern). Missing dataItem / empty condition → `Bad`. `observation.timestamp` → `SourceTimestamp` (not a separate node).
 
 ### 3.4 `IReadable` — `/current`
 

docs/plans/2026-07-15-sql-poll-driver-design.md

@@ -588,6 +588,40 @@ SQL Server client works cross-platform, so `Sql` runs on macOS dev too (unlike G
   `dialect.QuoteIdentifier` (which escapes/rejects embedded quote characters). A table/column string
   in a `TagConfig` is validated against the live catalog (or an allow-list) before it's ever quoted
   into text; an unknown identifier rejects the tag (→ `BadNodeIdUnknown`) rather than executing.
+
+  **Implemented (Gitea #496).** `SqlCatalogGate` + `SqlCatalogLoader`, run from
+  `SqlDriver.InitializeAsync` after the liveness check and before the driver reports Healthy. Shape,
+  and the decisions worth knowing before touching it:
+
+  - **The catalog's spelling is substituted, not merely checked.** An accepted identifier is rewritten
+    to the string the catalog returned, so the text quoted into a poll query is one this driver read
+    back out of `ListSchemas`/`ListTables`/`ListColumns` — not operator input. Matching is
+    exact-ordinal first, then a *unique* case-insensitive hit (SQL Server's default collation is CI, so
+    case variants have always worked and rejecting them would break valid configs); an ambiguous CI
+    match under a case-sensitive collation is refused rather than guessed, because picking one would
+    publish another column's data under the operator's node.
+  - **Charset check first, catalog lookup second.** Each identifier goes through `QuoteIdentifier` for
+    its rejection rules *before* being looked up, so a name carrying a control or Unicode format
+    character is rejected **without its value being echoed** into a log line (Trojan-Source). A name
+    that passes is safe to render, which is why catalog-miss messages *do* name it — an operator
+    hunting a typo has to see what they wrote.
+  - **Rejection is per-tag and keeps the node.** The rejected tag is dropped from the *polled* table
+    but stays in the *authored* table, so it still materializes as a node and reads
+    `BadNodeIdUnknown` (§8.1's specified outcome) instead of vanishing from the address space. Every
+    drop is logged at Warning with the tag, the field and the reason.
+  - **A catalog that cannot be read faults Initialize; it does not reject every tag.** An unreadable
+    catalog is the *absence* of evidence about the tags, not evidence against them — rejecting all of
+    them would serve a confidently-empty address space and send the operator hunting typos that do not
+    exist. Zero visible schemas is treated the same way, because that is what a missing GRANT looks
+    like. Faulting lands `DriverInstanceActor` in Reconnecting with its retry timer running.
+  - **Bounded load:** one schema-list query, one default-schema scalar (`ISqlDialect.DefaultSchemaSql`,
+    added for this — an unqualified `TagValues` must resolve in whatever schema the *server* says, not
+    a guessed `dbo`), then one `ListTables` per distinct authored schema and one `ListColumns` per
+    distinct authored relation. It never enumerates the whole catalog, and the load runs under the same
+    wall-clock bound as the liveness check (R2-01 / STAB-14).
+  - **Accepted v1 limitation:** a 3-part `db.schema.table` (or a linked-server name) addresses a
+    catalog this connection cannot enumerate, so it cannot be allow-listed and is rejected with a
+    message pointing at the fix — expose the data through a view in the connected database.
 - **Treat any code path that builds SQL by string-concatenating a tag field as a defect** — enforce
   with a review checklist item + a unit test that feeds a malicious `keyValue`/`table`
   (`'; DROP TABLE …`) and asserts it either binds harmlessly (value) or is rejected (identifier),
@@ -607,8 +641,15 @@ comment) and the env-overridable ConfigDb connection string:
   file. Direct env read (not `IConfiguration`) is deliberate: the factory registry materializes
   drivers via a static `(id, json)` closure (Modbus pattern) with no `IConfiguration` in reach, so
   this keeps the factory shape unchanged.
-- If an inline `connectionString` is ever permitted (dev convenience only), the AdminUI **redacts** it
-  in display/logging and flags it dev-only.
+- **An inline `connectionString` is not permitted at all** — the earlier "dev convenience, redacted in
+  the UI" carve-out is withdrawn (Gitea #498). Redaction only hides a credential that has *already been
+  written* to the config DB and replicated to every node's artifact cache. `SqlDriverConfigDto` has no
+  such property and `UnmappedMemberHandling.Skip` drops the key on read, but that protects only the read
+  path; config blobs are schemaless JSON columns, so nothing stopped the key being **written**.
+  `DraftValidator.ValidateSqlConnectionStringNotPersisted` now fails the deploy
+  (`SqlConnectionStringPersisted`) for a `connectionString` key at the top level of a Sql driver's
+  `DriverConfig` **or** of the `DeviceConfig` of any device beneath it (the two are merged before the DTO
+  sees them). The key is matched case-insensitively, and the error text never echoes the value.
 - **Never log the resolved connection string.** Log only provider + server host + database name.
 - Prefer integrated/managed auth where the estate supports it (`Integrated Security=true` / Azure AD /
   Kerberos) so no password transits config at all.

docs/plans/2026-07-16-v3-batch4-PR.md

@@ -94,7 +94,14 @@ dual-namespace + event-delivery), Runtime 377 (+ VT reassert regression), AdminU
 
 ## Documented follow-ups (non-blocking)
 
-- **Scripted-alarm redeploy recovery (CONFIRMED pre-existing bug, deferred — deserves its own careful fix). Filed as issue #487.**
+- **Scripted-alarm redeploy recovery — FIXED (issue #487), see `docs/ScriptedAlarms.md` §"Post-(re)load
+  condition-node re-assert".** Landed as the proposed shape below: `ScriptedAlarmHostActor.ReassertConditionNodes`
+  in `OnAlarmsLoaded`, node-only, never the `alerts` topic. Two deviations from the sketch, both deliberate:
+  it reads a new `ScriptedAlarmEngine.GetProjections()` rather than `GetState(alarmId)` + `LoadedAlarmIds`
+  (a projection also carries the definition's severity, the resolved message template, and the last-observed
+  worst-input quality — `GetState` alone would have clobbered severity/message on the node); and it skips
+  alarms sitting in the Part 9 no-event position, so a deploy where nothing is in alarm writes no condition
+  nodes at all. The original deferral text follows for context.
   The scripted-alarm Part 9 condition node has the same redeploy-reset race the VT `ReassertValue` fix closed:
   `RebuildAddressSpace` clears `_alarmConditions` and `MaterialiseScriptedAlarms` recreates each condition
   fresh/normal, but `ScriptedAlarmEngine.LoadAsync` reloads from the persisted state and yields

src/Core/ZB.MOM.WW.OtOpcUa.Configuration/Validation/DraftValidator.cs

@@ -41,9 +41,100 @@ public static class DraftValidator
         ValidateUnsEffectiveLeafUniqueness(draft, errors);
         ValidateEquipReferenceResolution(draft, errors);
         ValidateCalculationTags(draft, errors);
+        ValidateSqlConnectionStringNotPersisted(draft, errors);
         return errors;
     }
 
+    /// <summary>
+    ///     The <c>Sql</c> driver's "a pasted literal connection string is never persisted" guarantee, enforced
+    ///     at the deploy gate (Gitea #498).
+    /// </summary>
+    /// <remarks>
+    ///     <para>A Sql driver names its credentials indirectly — <c>connectionStringRef</c> resolves from the
+    ///     environment / secret store at Initialize — so a deployed artifact carries no database password.
+    ///     Until now that guarantee rested entirely on the <b>read</b> path: <c>SqlDriverConfigDto</c> has no
+    ///     <c>connectionString</c> property and <c>UnmappedMemberHandling.Skip</c> drops the key on
+    ///     deserialization. Nothing stopped the key being <b>written</b>. Config blobs are schemaless JSON
+    ///     columns, and the fallback authoring pattern for a driver without a typed form is a raw-JSON
+    ///     textarea, so an operator pasting <c>{"connectionString":"Server=…;Password=…"}</c> would put a live
+    ///     credential in the ConfigDb — persisted, replicated to every node's artifact cache, and readable by
+    ///     anyone with config access — while the runtime silently ignored it and the driver failed to connect.
+    ///     Discarding a secret on read is not the same as refusing to store it.</para>
+    ///     <para>Checked on <b>both</b> config surfaces a Sql driver reads: the instance's
+    ///     <see cref="DriverInstance.DriverConfig"/> and the <see cref="Device.DeviceConfig"/> of every device
+    ///     beneath it, because the two are merged before the DTO sees them — a credential pasted into the
+    ///     device blob lands in exactly the same place.</para>
+    ///     <para>The key is matched <b>case-insensitively</b>: <c>System.Text.Json</c> binds
+    ///     <c>ConnectionString</c> to a <c>connectionString</c> property by default, so a case variant is the
+    ///     same key, not a different one. Only the top level is scanned — the DTO is flat, so a nested
+    ///     occurrence cannot bind and is not the credential-shaped mistake this rule exists to catch.</para>
+    ///     <para><b>The message never echoes the value.</b> Validation errors reach the AdminUI, the deploy
+    ///     log and the audit trail; repeating the offending string there would leak the very credential the
+    ///     rule is refusing to store.</para>
+    /// </remarks>
+    private static void ValidateSqlConnectionStringNotPersisted(DraftSnapshot draft, List<ValidationError> errors)
+    {
+        const string ForbiddenKey = "connectionString";
+
+        var sqlInstanceIds = draft.DriverInstances
+            .Where(d => string.Equals(d.DriverType, Core.Abstractions.DriverTypeNames.Sql, StringComparison.Ordinal))
+            .Select(d => d.DriverInstanceId)
+            .ToHashSet(StringComparer.Ordinal);
+        if (sqlInstanceIds.Count == 0) return;
+
+        foreach (var d in draft.DriverInstances)
+        {
+            if (!sqlInstanceIds.Contains(d.DriverInstanceId)) continue;
+            if (!HasTopLevelKey(d.DriverConfig, ForbiddenKey)) continue;
+            errors.Add(new("SqlConnectionStringPersisted",
+                $"Sql driver instance '{d.DriverInstanceId}' has a '{ForbiddenKey}' key in its DriverConfig. " +
+                "A Sql driver must name its credentials indirectly via 'connectionStringRef', which resolves " +
+                "from the environment / secret store at Initialize; a literal connection string here would be " +
+                "stored in the config database and replicated to every node, and the runtime ignores it anyway. " +
+                "Remove the key and set 'connectionStringRef'.",
+                d.DriverInstanceId));
+        }
+
+        foreach (var dev in draft.Devices)
+        {
+            if (!sqlInstanceIds.Contains(dev.DriverInstanceId)) continue;
+            if (!HasTopLevelKey(dev.DeviceConfig, ForbiddenKey)) continue;
+            errors.Add(new("SqlConnectionStringPersisted",
+                $"Device '{dev.DeviceId}' on Sql driver instance '{dev.DriverInstanceId}' has a " +
+                $"'{ForbiddenKey}' key in its DeviceConfig. DeviceConfig is merged onto DriverConfig before " +
+                "the driver reads it, so this is the same leak: use 'connectionStringRef' on the driver instead.",
+                dev.DeviceId));
+        }
+    }
+
+    /// <summary>
+    ///     True when <paramref name="json"/> is a JSON object carrying <paramref name="key"/> at its top level,
+    ///     matched case-insensitively. Never throws — a blank, malformed or non-object blob simply has no keys,
+    ///     and shaping the config JSON is another rule's job.
+    /// </summary>
+    /// <param name="json">The config blob to inspect.</param>
+    /// <param name="key">The property name to look for.</param>
+    /// <returns><see langword="true"/> when the key is present at the top level.</returns>
+    private static bool HasTopLevelKey(string? json, string key)
+    {
+        if (string.IsNullOrWhiteSpace(json)) return false;
+        try
+        {
+            using var doc = System.Text.Json.JsonDocument.Parse(json);
+            if (doc.RootElement.ValueKind != System.Text.Json.JsonValueKind.Object) return false;
+            foreach (var property in doc.RootElement.EnumerateObject())
+            {
+                if (string.Equals(property.Name, key, StringComparison.OrdinalIgnoreCase)) return true;
+            }
+
+            return false;
+        }
+        catch (System.Text.Json.JsonException)
+        {
+            return false;
+        }
+    }
+
     /// <summary>WP7 Calculation-driver deploy gates. For every tag bound to a <c>Calculation</c> driver:
     /// <list type="number">
     ///   <item><b>scriptId existence</b> — the tag's <c>TagConfig.scriptId</c> must be present and resolve to

src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/DriverTypeNames.cs

@@ -53,6 +53,9 @@ public static class DriverTypeNames
     /// <summary>Calculation pseudo-driver — tags computed by C# scripts over other tags' live values.</summary>
     public const string Calculation = "Calculation";
 
+    /// <summary>Read-only SQL Server table/view poller — publishes columns as OPC UA variables.</summary>
+    public const string Sql = "Sql";
+
     /// <summary>
     ///     Every driver-type string declared above, for callers that need to enumerate
     ///     the full set (e.g. validation of an authored <c>DriverType</c>).
@@ -68,5 +71,6 @@ public static class DriverTypeNames
         OpcUaClient,
         Galaxy,
         Calculation,
+        Sql,
     ];
 }

src/Core/ZB.MOM.WW.OtOpcUa.Core.ScriptedAlarms/ScriptedAlarmEngine.cs

@@ -334,6 +334,48 @@ public sealed class ScriptedAlarmEngine : IDisposable
     public IReadOnlyCollection<AlarmConditionState> GetAllStates()
         => _alarms.Values.Select(a => a.Condition).ToArray();
 
+    /// <summary>
+    ///     #487 — the currently-held condition of every loaded alarm, packaged with the definition's
+    ///     severity, the rendered message template and the last-observed input quality, i.e. everything
+    ///     a caller needs to <b>project</b> the alarm onto an OPC UA condition node without waiting for
+    ///     the next transition.
+    /// </summary>
+    /// <remarks>
+    ///     <para>
+    ///         <b>This is a read, not an emission.</b> It deliberately returns a distinct type rather
+    ///         than a <see cref="ScriptedAlarmEvent"/>, and it never touches <see cref="OnEvent"/>. A
+    ///         still-active alarm produces <see cref="EmissionKind.None"/> at load (there is no
+    ///         transition to report), so the transition stream cannot carry the current state — that is
+    ///         exactly why the caller needs this. Routing these through the emission path instead would
+    ///         append a duplicate historian / <c>alerts</c> row on every deploy, so the shape here is
+    ///         intentionally one the emission machinery cannot consume.
+    ///     </para>
+    ///     <para>
+    ///         <b>Synchronization.</b> Reads <c>_alarms</c> and <c>_valueCache</c> — both
+    ///         <see cref="ConcurrentDictionary{TKey, TValue}"/> — without taking <c>_evalGate</c>, the
+    ///         same posture as <see cref="GetState"/> / <see cref="GetAllStates"/>. Each projection is
+    ///         individually coherent; the set as a whole is not an atomic snapshot across a concurrent
+    ///         re-evaluation. That is sufficient for the node-projection use: an evaluation racing this
+    ///         read publishes its own transition through the normal path.
+    ///     </para>
+    /// </remarks>
+    /// <returns>One projection per loaded alarm; empty before the first <see cref="LoadAsync"/>.</returns>
+    public IReadOnlyList<ScriptedAlarmProjection> GetProjections()
+    {
+        var projections = new List<ScriptedAlarmProjection>(_alarms.Count);
+        foreach (var (alarmId, state) in _alarms)
+        {
+            projections.Add(new ScriptedAlarmProjection(
+                AlarmId: alarmId,
+                Severity: state.Definition.Severity,
+                Message: MessageTemplate.Resolve(state.Definition.MessageTemplate, TryLookup),
+                Condition: state.Condition,
+                WorstInputStatusCode: LastWorstStatus(alarmId)));
+        }
+
+        return projections;
+    }
+
     /// <summary>Acknowledges the specified alarm on behalf of the given user.</summary>
     /// <param name="alarmId">The alarm identifier.</param>
     /// <param name="user">The user performing the acknowledgment.</param>
@@ -974,6 +1016,26 @@ public sealed record ScriptedAlarmEvent(
     // the top-2 severity bits. Default 0u == Good keeps every existing constructor call unchanged.
     uint WorstInputStatusCode = 0u);
 
+/// <summary>
+///     #487 — a loaded alarm's current condition, ready to be projected onto its OPC UA node.
+///     Produced by <see cref="ScriptedAlarmEngine.GetProjections"/> on demand; it is <b>not</b> an
+///     emission and never travels the <see cref="ScriptedAlarmEngine.OnEvent"/> path, so it can never
+///     become an <c>alerts</c> row or a historian record. Deliberately a separate type from
+///     <see cref="ScriptedAlarmEvent"/> — it carries no <see cref="EmissionKind"/>, so there is nothing
+///     for a future refactor to mistake for a transition.
+/// </summary>
+/// <param name="AlarmId">The alarm identifier (also its OPC UA condition NodeId).</param>
+/// <param name="Severity">The definition's severity bucket.</param>
+/// <param name="Message">The message template resolved against the current value cache.</param>
+/// <param name="Condition">The Part 9 condition state the engine currently holds.</param>
+/// <param name="WorstInputStatusCode">The last-observed worst OPC UA StatusCode across the alarm's inputs.</param>
+public sealed record ScriptedAlarmProjection(
+    string AlarmId,
+    AlarmSeverity Severity,
+    string Message,
+    AlarmConditionState Condition,
+    uint WorstInputStatusCode);
+
 /// <summary>
 ///     Upstream source abstraction — intentionally identical shape to the virtual-tag
 ///     engine's so Stream G can compose them behind one driver bridge.

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbCip/AbCipStatusMapper.cs

@@ -35,7 +35,7 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.AbCip;
 public static class AbCipStatusMapper
 {
     public const uint Good = 0u;
-    public const uint GoodMoreData = 0x00A70000u;
+    public const uint GoodMoreData = 0x00A60000u;
     public const uint BadInternalError = 0x80020000u;
     public const uint BadNodeIdUnknown = 0x80340000u;
     public const uint BadNotWritable = 0x803B0000u;
@@ -44,7 +44,7 @@ public static class AbCipStatusMapper
     public const uint BadDeviceFailure = 0x808B0000u;
     public const uint BadCommunicationError = 0x80050000u;
     public const uint BadTimeout = 0x800A0000u;
-    public const uint BadTypeMismatch = 0x80730000u;
+    public const uint BadTypeMismatch = 0x80740000u;
 
     /// <summary>Map a CIP general-status byte to an OPC UA StatusCode.</summary>
     /// <param name="status">The CIP general-status byte value.</param>

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy/AbLegacyStatusMapper.cs

@@ -10,7 +10,7 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.AbLegacy;
 public static class AbLegacyStatusMapper
 {
     public const uint Good = 0u;
-    public const uint GoodMoreData = 0x00A70000u;
+    public const uint GoodMoreData = 0x00A60000u;
     public const uint BadInternalError = 0x80020000u;
     public const uint BadNodeIdUnknown = 0x80340000u;
     public const uint BadNotWritable = 0x803B0000u;
@@ -19,7 +19,7 @@ public static class AbLegacyStatusMapper
     public const uint BadDeviceFailure = 0x808B0000u;
     public const uint BadCommunicationError = 0x80050000u;
     public const uint BadTimeout = 0x800A0000u;
-    public const uint BadTypeMismatch = 0x80730000u;
+    public const uint BadTypeMismatch = 0x80740000u;
 
     /// <summary>
     ///     Map a libplctag return/status code to an OPC UA StatusCode. The integer passed here

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS/FocasStatusMapper.cs

@@ -17,7 +17,7 @@ public static class FocasStatusMapper
     public const uint BadDeviceFailure = 0x808B0000u;
     public const uint BadCommunicationError = 0x80050000u;
     public const uint BadTimeout = 0x800A0000u;
-    public const uint BadTypeMismatch = 0x80730000u;
+    public const uint BadTypeMismatch = 0x80740000u;
 
     /// <summary>
     ///     Map common FWLIB <c>EW_*</c> return codes. The values below match Fanuc's published

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/GalaxyDriver.cs

@@ -856,7 +856,7 @@ public sealed class GalaxyDriver
             {
                 rejectedTcs.TrySetResult(new DataValueSnapshot(
                     Value: null,
-                    StatusCode: 0x80000000u, // Bad
+                    StatusCode: StatusCodeMap.Bad,
                     SourceTimestampUtc: null,
                     ServerTimestampUtc: DateTime.UtcNow));
             }
@@ -875,7 +875,7 @@ public sealed class GalaxyDriver
                 {
                     tcs.TrySetResult(new DataValueSnapshot(
                         Value: null,
-                        StatusCode: 0x800B0000u, // BadTimeout
+                        StatusCode: StatusCodeMap.BadTimeout,
                         SourceTimestampUtc: null,
                         ServerTimestampUtc: DateTime.UtcNow));
                 }

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/StatusCodeMap.cs

@@ -26,14 +26,23 @@ internal static class StatusCodeMap
 {
     // OPC UA Part 4 standard StatusCodes — top-byte categories are 0x00 (Good),
     // 0x40 (Uncertain), 0x80 (Bad). Specific codes layer onto the category byte.
+    //
+    // The substatus nibbles are NOT derivable from the OPC DA quality byte this mapper consumes —
+    // they are an unrelated OPC UA enumeration and have to be looked up. Five constants here were
+    // originally written as though the DA byte could be shifted into the substatus position, which
+    // produced values naming entirely different UA codes (Gitea #497): UncertainLastUsableValue held
+    // UncertainDataSubNormal's value, UncertainSubNormal held UncertainNoCommunicationLastUsableValue's,
+    // and GoodLocalOverride / UncertainSensorNotAccurate / UncertainEngineeringUnitsExceeded held values
+    // that are not OPC UA status codes at all. StatusCodeParityTests now checks every constant below
+    // against the pinned SDK's Opc.Ua.StatusCodes.
 
     public const uint Good                            = 0x00000000u;
-    public const uint GoodLocalOverride               = 0x00D80000u;
+    public const uint GoodLocalOverride               = 0x00960000u;
     public const uint Uncertain                       = 0x40000000u;
-    public const uint UncertainLastUsableValue        = 0x40A40000u;
-    public const uint UncertainSensorNotAccurate      = 0x408D0000u;
-    public const uint UncertainEngineeringUnitsExceeded = 0x408E0000u;
-    public const uint UncertainSubNormal              = 0x408F0000u;
+    public const uint UncertainLastUsableValue        = 0x40900000u;
+    public const uint UncertainSensorNotAccurate      = 0x40930000u;
+    public const uint UncertainEngineeringUnitsExceeded = 0x40940000u;
+    public const uint UncertainSubNormal              = 0x40950000u;
     public const uint Bad                             = 0x80000000u;
     public const uint BadConfigurationError           = 0x80890000u;
     public const uint BadNotConnected                 = 0x808A0000u;
@@ -44,6 +53,14 @@ internal static class StatusCodeMap
     public const uint BadWaitingForInitialData        = 0x80320000u;
     public const uint BadInternalError                = 0x80020000u;
 
+    /// <summary>
+    ///     Fills a still-pending read when the caller's token fires before the gateway answers. Named here
+    ///     rather than written inline at the call site so <c>StatusCodeParityTests</c> can reflect over it —
+    ///     an inline literal is invisible to that guard, which is exactly how this constant spent its life
+    ///     as <c>0x800B0000</c> (<c>BadServiceUnsupported</c>) under a <c>// BadTimeout</c> comment.
+    /// </summary>
+    public const uint BadTimeout                      = 0x800A0000u;
+
     /// <summary>
     ///     Map a raw OPC DA quality byte (the low byte of an OPC DA <c>OpcQuality</c> ushort,
     ///     which is what Wonderware Historian + MXAccess surface as <c>OPCITEMSTATE.qLong</c>'s

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway/Mapping/GatewayQualityMapper.cs

@@ -18,29 +18,29 @@ internal static class GatewayQualityMapper
     public static uint Map(byte q) => q switch
     {
         // Good family (192+)
-        192 => 0x00000000u,             // Good
-        216 => 0x00D80000u,             // Good_LocalOverride
+        192 => HistorianStatusCodes.Good,
+        216 => HistorianStatusCodes.GoodLocalOverride,
 
         // Uncertain family (64-191)
-        64 => 0x40000000u,              // Uncertain
-        68 => 0x40900000u,              // Uncertain_LastUsableValue
-        80 => 0x40930000u,              // Uncertain_SensorNotAccurate
-        84 => 0x40940000u,              // Uncertain_EngineeringUnitsExceeded
-        88 => 0x40950000u,              // Uncertain_SubNormal
+        64 => HistorianStatusCodes.Uncertain,
+        68 => HistorianStatusCodes.UncertainLastUsableValue,
+        80 => HistorianStatusCodes.UncertainSensorNotAccurate,
+        84 => HistorianStatusCodes.UncertainEngineeringUnitsExceeded,
+        88 => HistorianStatusCodes.UncertainSubNormal,
 
         // Bad family (0-63)
-        0 => 0x80000000u,               // Bad
-        4 => 0x80890000u,               // Bad_ConfigurationError
-        8 => 0x808A0000u,               // Bad_NotConnected
-        12 => 0x808B0000u,              // Bad_DeviceFailure
-        16 => 0x808C0000u,              // Bad_SensorFailure
-        20 => 0x80050000u,              // Bad_CommunicationError
-        24 => 0x808D0000u,              // Bad_OutOfService
-        32 => 0x80320000u,              // Bad_WaitingForInitialData
+        0 => HistorianStatusCodes.Bad,
+        4 => HistorianStatusCodes.BadConfigurationError,
+        8 => HistorianStatusCodes.BadNotConnected,
+        12 => HistorianStatusCodes.BadDeviceFailure,
+        16 => HistorianStatusCodes.BadSensorFailure,
+        20 => HistorianStatusCodes.BadCommunicationError,
+        24 => HistorianStatusCodes.BadOutOfService,
+        32 => HistorianStatusCodes.BadWaitingForInitialData,
 
         // Unknown — fall back to category bucket so callers still get something usable.
-        _ when q >= 192 => 0x00000000u,
-        _ when q >= 64 => 0x40000000u,
-        _ => 0x80000000u,
+        _ when q >= 192 => HistorianStatusCodes.Good,
+        _ when q >= 64 => HistorianStatusCodes.Uncertain,
+        _ => HistorianStatusCodes.Bad,
     };
 }

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway/Mapping/HistorianStatusCodes.cs

@@ -0,0 +1,75 @@
+namespace ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.Mapping;
+
+/// <summary>
+///     The OPC UA status codes this driver publishes, as named constants.
+/// </summary>
+/// <remarks>
+///     <para>The driver layer is deliberately free of an OPC UA SDK reference, so status codes are spelled
+///     as bare <c>uint</c>s. The cost of that is a value nobody checks against the name it is written
+///     under — the defect class Gitea #497 found in six places across four drivers, one of them the
+///     <c>BadNoData</c> in <see cref="SampleMapper"/> that was really <c>BadServerHalted</c>.</para>
+///     <para><b>Named, not inline, on purpose.</b> <c>StatusCodeParityTests</c> guards these by reflecting
+///     over <c>const uint</c> fields and comparing each against <c>Opc.Ua.StatusCodes</c> in the pinned SDK.
+///     A literal written at a call site is invisible to that guard, which is exactly how
+///     <see cref="GatewayQualityMapper"/> kept an incorrect <c>Good_LocalOverride</c> through every test it
+///     had. Add a constant here rather than a literal in a <c>switch</c> arm.</para>
+/// </remarks>
+internal static class HistorianStatusCodes
+{
+    // ---- Good family ----
+
+    /// <summary>The value is good; no qualification.</summary>
+    public const uint Good = 0x00000000u;
+
+    /// <summary>The value has been overridden locally (OPC DA quality 216).</summary>
+    public const uint GoodLocalOverride = 0x00960000u;
+
+    // ---- Uncertain family ----
+
+    /// <summary>The value is uncertain; no specific reason.</summary>
+    public const uint Uncertain = 0x40000000u;
+
+    /// <summary>Communication has failed; the last known value is returned (OPC DA quality 68).</summary>
+    public const uint UncertainLastUsableValue = 0x40900000u;
+
+    /// <summary>The sensor is known not to be accurate (OPC DA quality 80).</summary>
+    public const uint UncertainSensorNotAccurate = 0x40930000u;
+
+    /// <summary>The value is outside the engineering-unit range for the sensor (OPC DA quality 84).</summary>
+    public const uint UncertainEngineeringUnitsExceeded = 0x40940000u;
+
+    /// <summary>The value is derived from fewer sources than required (OPC DA quality 88).</summary>
+    public const uint UncertainSubNormal = 0x40950000u;
+
+    // ---- Bad family ----
+
+    /// <summary>The value is bad; no specific reason.</summary>
+    public const uint Bad = 0x80000000u;
+
+    /// <summary>A configuration problem prevents the value being produced (OPC DA quality 4).</summary>
+    public const uint BadConfigurationError = 0x80890000u;
+
+    /// <summary>The source is not connected (OPC DA quality 8).</summary>
+    public const uint BadNotConnected = 0x808A0000u;
+
+    /// <summary>The device reported a failure (OPC DA quality 12).</summary>
+    public const uint BadDeviceFailure = 0x808B0000u;
+
+    /// <summary>The sensor reported a failure (OPC DA quality 16).</summary>
+    public const uint BadSensorFailure = 0x808C0000u;
+
+    /// <summary>Communication with the source failed (OPC DA quality 20).</summary>
+    public const uint BadCommunicationError = 0x80050000u;
+
+    /// <summary>The source is out of service (OPC DA quality 24).</summary>
+    public const uint BadOutOfService = 0x808D0000u;
+
+    /// <summary>No initial value has arrived from the source yet (OPC DA quality 32).</summary>
+    public const uint BadWaitingForInitialData = 0x80320000u;
+
+    /// <summary>
+    ///     The historian returned no data for the requested tag/interval. Distinct from a transport
+    ///     failure: the query succeeded and the answer was empty.
+    /// </summary>
+    public const uint BadNoData = 0x809B0000u;
+}

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway/Mapping/SampleMapper.cs

@@ -10,8 +10,8 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.Mapping;
 /// </summary>
 internal static class SampleMapper
 {
-    private const uint StatusGood = 0x00000000u;
-    private const uint StatusBadNoData = 0x800E0000u;
+    private const uint StatusGood = HistorianStatusCodes.Good;
+    private const uint StatusBadNoData = HistorianStatusCodes.BadNoData;
 
     /// <summary>OPC DA "Good" family floor — a quality byte at/above this carries usable data.</summary>
     private const byte GoodQualityFloor = 192;

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql/ISqlDialect.cs

@@ -14,11 +14,13 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.Sql;
 ///     parameterized in SQL, so the few that must appear as text are emitted through
 ///     <see cref="QuoteIdentifier"/>. Any code path that builds SQL by concatenating an authored tag field
 ///     <em>without</em> going through <see cref="QuoteIdentifier"/> is a defect (design §8.1).</para>
-///     <para><b>Not yet implemented:</b> design §8.1 also specifies that an authored table/column is
-///     validated against the live catalog before it is ever quoted into text, so that an unknown identifier
-///     rejects the tag. No such gate exists yet — an identifier reaches <see cref="QuoteIdentifier"/>
-///     straight from the authored <c>TagConfig</c> blob, so <b>quoting is currently the only defence</b>,
-///     not a backstop behind an upstream filter. Scrutinise it accordingly.</para>
+///     <para><b>Quoting is the backstop, not the only defence.</b> Design §8.1's catalog gate is
+///     implemented: <see cref="SqlCatalogGate"/> resolves every authored table/column against the live
+///     catalog at Initialize and <b>replaces it with the catalog's own spelling</b>, so an identifier
+///     reaching <see cref="QuoteIdentifier"/> on the poll path is a string this driver read back out of
+///     <see cref="ListSchemasSql"/> / <see cref="ListTablesSql"/> / <see cref="ListColumnsSql"/> — not
+///     operator input. An identifier that resolves to nothing rejects its tag (which then publishes
+///     <c>BadNodeIdUnknown</c>) rather than being quoted into a query against a nonexistent object.</para>
 ///     <para>Public because <c>Driver.Sql.Browser</c> consumes it — the catalog SQL <em>is</em> the browse
 ///     engine, so it is shared rather than duplicated. Implementations own their provider package;
 ///     <b>no provider-specific type appears in this signature</b> (<see cref="Factory"/> is the abstract
@@ -89,6 +91,20 @@ public interface ISqlDialect
     /// <summary>Catalog query listing schemas — the browser's <c>RootAsync</c> level. Takes no parameters.</summary>
     string ListSchemasSql { get; }
 
+    /// <summary>
+    ///     Scalar query returning the schema an <b>unqualified</b> object name resolves to for the connecting
+    ///     principal — T-SQL's <c>SELECT SCHEMA_NAME()</c>. Takes no parameters.
+    /// </summary>
+    /// <remarks>
+    ///     <para>Needed by <see cref="SqlCatalogGate"/>: a tag authored as <c>TagValues</c> rather than
+    ///     <c>dbo.TagValues</c> has to be looked up in <em>some</em> schema, and guessing <c>dbo</c> would be a
+    ///     silent lie on any estate that maps its service accounts to their own default schema. Asking the
+    ///     server is the only answer that matches how the poll query itself will resolve the name.</para>
+    ///     <para>It is a <em>query</em> rather than a name because the answer is per-connection, not per-dialect
+    ///     — the same dialect resolves differently for two different logins.</para>
+    /// </remarks>
+    string DefaultSchemaSql { get; }
+
     /// <summary>Catalog query listing tables + views in one schema — the browser's schema-expand level. Bind <c>@schema</c>.</summary>
     string ListTablesSql { get; }
 

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql/SqlCatalog.cs

@@ -0,0 +1,137 @@
+namespace ZB.MOM.WW.OtOpcUa.Driver.Sql;
+
+/// <summary>
+///     An immutable snapshot of the parts of a database's catalog the authored tags actually name — the
+///     allow-list design §8.1 requires identifiers to come from.
+///     <para><b>This type holds catalog strings only.</b> Every name in it was read back out of
+///     <see cref="ISqlDialect.ListSchemasSql"/> / <see cref="ISqlDialect.ListTablesSql"/> /
+///     <see cref="ISqlDialect.ListColumnsSql"/>; nothing an operator typed is ever stored here. That is what
+///     lets <see cref="SqlCatalogGate"/> hand the planner catalog spellings rather than authored ones, so the
+///     identifier text in an emitted query is a string the database gave us.</para>
+///     <para><b>Deliberately partial.</b> Only the schemas/tables the authored tags name are loaded — a
+///     driver polling three tables must not enumerate a warehouse's ten thousand. A name absent from this
+///     snapshot therefore means "not found <em>when we looked</em>", which is exactly the question the gate
+///     asks.</para>
+/// </summary>
+public sealed class SqlCatalog
+{
+    private readonly IReadOnlyList<string> _schemas;
+
+    /// <summary>Canonical schema → canonical table names in it.</summary>
+    private readonly IReadOnlyDictionary<string, IReadOnlyList<string>> _tablesBySchema;
+
+    /// <summary>Canonical <c>schema.table</c> → that relation's canonical column names.</summary>
+    private readonly IReadOnlyDictionary<string, IReadOnlyList<string>> _columnsByTable;
+
+    /// <summary>Constructs a catalog snapshot.</summary>
+    /// <param name="defaultSchema">The schema an unqualified object name resolves to for this connection.</param>
+    /// <param name="schemas">Every schema the connection can see.</param>
+    /// <param name="tablesBySchema">Canonical schema → its tables/views.</param>
+    /// <param name="columnsByTable">Canonical <c>schema.table</c> → its columns.</param>
+    internal SqlCatalog(
+        string defaultSchema,
+        IReadOnlyList<string> schemas,
+        IReadOnlyDictionary<string, IReadOnlyList<string>> tablesBySchema,
+        IReadOnlyDictionary<string, IReadOnlyList<string>> columnsByTable)
+    {
+        DefaultSchema = defaultSchema;
+        _schemas = schemas;
+        _tablesBySchema = tablesBySchema;
+        _columnsByTable = columnsByTable;
+    }
+
+    /// <summary>The schema an unqualified authored object name is resolved in.</summary>
+    public string DefaultSchema { get; }
+
+    /// <summary>Resolves an authored schema name to the catalog's own spelling.</summary>
+    /// <param name="authored">The authored schema, or null/blank for the default schema.</param>
+    /// <param name="canonical">The catalog's spelling, when resolved.</param>
+    /// <returns><see langword="true"/> when the schema exists (or the default schema is used).</returns>
+    public bool TryResolveSchema(string? authored, out string canonical)
+    {
+        if (string.IsNullOrWhiteSpace(authored))
+        {
+            canonical = DefaultSchema;
+            return true;
+        }
+
+        return TryMatch(_schemas, authored, out canonical);
+    }
+
+    /// <summary>Resolves an authored table/view name within a canonical schema.</summary>
+    /// <param name="canonicalSchema">The schema, already resolved through <see cref="TryResolveSchema"/>.</param>
+    /// <param name="authored">The authored table or view name.</param>
+    /// <param name="canonical">The catalog's spelling, when resolved.</param>
+    /// <returns><see langword="true"/> when the relation exists in that schema.</returns>
+    public bool TryResolveTable(string canonicalSchema, string authored, out string canonical)
+    {
+        canonical = string.Empty;
+        return _tablesBySchema.TryGetValue(canonicalSchema, out var tables)
+               && TryMatch(tables, authored, out canonical);
+    }
+
+    /// <summary>Resolves an authored column name within a canonical relation.</summary>
+    /// <param name="canonicalSchema">The resolved schema.</param>
+    /// <param name="canonicalTable">The resolved table or view.</param>
+    /// <param name="authored">The authored column name.</param>
+    /// <param name="canonical">The catalog's spelling, when resolved.</param>
+    /// <returns><see langword="true"/> when the column exists on that relation.</returns>
+    public bool TryResolveColumn(
+        string canonicalSchema, string canonicalTable, string authored, out string canonical)
+    {
+        canonical = string.Empty;
+        return _columnsByTable.TryGetValue(QualifiedKey(canonicalSchema, canonicalTable), out var columns)
+               && TryMatch(columns, authored, out canonical);
+    }
+
+    /// <summary>The dictionary key for a canonical relation.</summary>
+    /// <param name="schema">The canonical schema.</param>
+    /// <param name="table">The canonical table.</param>
+    /// <returns>The composite key.</returns>
+    internal static string QualifiedKey(string schema, string table) => schema + "." + table;
+
+    /// <summary>
+    ///     Matches an authored name against catalog spellings: an exact (ordinal) hit wins, otherwise a
+    ///     <b>unique</b> case-insensitive hit is accepted and its catalog spelling returned.
+    /// </summary>
+    /// <remarks>
+    ///     <para><b>Why case-insensitive at all.</b> SQL Server's default collation is case-insensitive, so
+    ///     <c>num_value</c> and <c>NUM_VALUE</c> genuinely name the same column and both work today. Matching
+    ///     ordinally would reject configurations that have always been valid — a gate that breaks working
+    ///     deployments is not defence in depth.</para>
+    ///     <para><b>Why exact-first, and why ambiguity fails.</b> On a case-<em>sensitive</em> collation a
+    ///     relation may legitimately carry both <c>Value</c> and <c>value</c>. Preferring the exact match keeps
+    ///     such a config resolving to what the operator wrote, and refusing to choose between two
+    ///     case-insensitive candidates is the only safe answer — silently picking one would publish a different
+    ///     column's data under the operator's node, which is worse than rejecting the tag.</para>
+    /// </remarks>
+    /// <param name="candidates">The catalog spellings to match against.</param>
+    /// <param name="authored">The authored name.</param>
+    /// <param name="canonical">The catalog's spelling, when matched.</param>
+    /// <returns><see langword="true"/> on an unambiguous match.</returns>
+    internal static bool TryMatch(IReadOnlyList<string> candidates, string authored, out string canonical)
+    {
+        foreach (var candidate in candidates)
+        {
+            if (!string.Equals(candidate, authored, StringComparison.Ordinal)) continue;
+            canonical = candidate;
+            return true;
+        }
+
+        canonical = string.Empty;
+        var matches = 0;
+        foreach (var candidate in candidates)
+        {
+            if (!string.Equals(candidate, authored, StringComparison.OrdinalIgnoreCase)) continue;
+            if (++matches > 1)
+            {
+                canonical = string.Empty;
+                return false;
+            }
+
+            canonical = candidate;
+        }
+
+        return matches == 1;
+    }
+}

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql/SqlCatalogGate.cs

@@ -0,0 +1,241 @@
+using ZB.MOM.WW.OtOpcUa.Driver.Sql.Contracts;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Sql;
+
+/// <summary>
+///     One tag the gate refused, and why. Carried rather than logged in place so the caller decides the log
+///     shape and the caller's tests can assert on the reason.
+/// </summary>
+/// <param name="RawPath">The rejected tag's identity — its RawPath, which is trusted structure, not blob content.</param>
+/// <param name="Field">The <see cref="SqlTagDefinition"/> field that failed (e.g. <c>ValueColumn</c>).</param>
+/// <param name="Reason">An operator-actionable explanation, safe to log.</param>
+public sealed record SqlCatalogRejection(string RawPath, string Field, string Reason);
+
+/// <summary>The outcome of applying a <see cref="SqlCatalog"/> to a set of authored tags.</summary>
+/// <param name="Accepted">
+///     The surviving definitions, <b>rewritten to catalog spellings</b>. Safe to hand to
+///     <see cref="SqlGroupPlanner"/>.
+/// </param>
+/// <param name="Rejected">Every tag the gate refused, in input order.</param>
+public sealed record SqlCatalogGateResult(
+    IReadOnlyList<SqlTagDefinition> Accepted,
+    IReadOnlyList<SqlCatalogRejection> Rejected);
+
+/// <summary>
+///     Design §8.1's identifier gate: validates every authored table/column against the live catalog
+///     <b>before</b> it can be quoted into SQL text, and replaces it with the catalog's own spelling.
+/// </summary>
+/// <remarks>
+///     <para><b>What this closes.</b> Until this existed, <see cref="ISqlDialect.QuoteIdentifier"/> was the
+///     sole defence: an identifier went from the authored <c>TagConfig</c> blob straight into a command text,
+///     bracket-quoted. The residual risk was bounded — a hostile name is quoted into one nonexistent object,
+///     the query fails after the connection opens, and the tag Bad-codes — but "bounded" is not "filtered",
+///     and the design promised a filter. With the gate in place the identifier text in an emitted query is a
+///     string this driver read back out of the catalog, so quoting is a backstop behind an allow-list rather
+///     than the whole story.</para>
+///     <para><b>Charset first, catalog second.</b> Each identifier is passed through
+///     <see cref="ISqlDialect.QuoteIdentifier"/> before it is looked up, purely for its rejection rules
+///     (control characters, Unicode format characters, over-length). That ordering is deliberate: a name that
+///     fails the charset check is rejected <em>without its value being echoed</em>, so nothing carrying a bidi
+///     override or a NUL can reach a log line through this type's rejection messages. A name that passes has
+///     been proven safe to render, which is why the catalog-miss messages can afford to name it — and they
+///     must, or an operator has no way to find the typo.</para>
+///     <para><b>Rejection is per-tag, never driver-wide.</b> A tag naming a dropped column is dropped from the
+///     driver's table, so its RawPath resolves to nothing and it publishes
+///     <see cref="SqlStatusCodes.BadNodeIdUnknown"/> — design §8.1's specified outcome — while every other tag
+///     on that database keeps polling. This mirrors the "one malformed blob must not take the whole driver
+///     down" rule the tag-table build already follows.</para>
+/// </remarks>
+public static class SqlCatalogGate
+{
+    /// <summary>
+    ///     The most name parts this gate can validate. A three-part <c>db.schema.table</c> (or a
+    ///     four-part linked-server name) addresses a catalog this connection's <c>INFORMATION_SCHEMA</c>
+    ///     cannot see, so it cannot be allow-listed.
+    /// </summary>
+    private const int MaxNameParts = 2;
+
+    /// <summary>
+    ///     Applies <paramref name="catalog"/> to <paramref name="definitions"/>, returning the accepted tags
+    ///     with catalog-spelled identifiers and the rejected ones with reasons.
+    /// </summary>
+    /// <param name="definitions">The authored definitions, as parsed from their <c>TagConfig</c> blobs.</param>
+    /// <param name="catalog">The catalog snapshot to validate against.</param>
+    /// <param name="dialect">Supplies the identifier charset rules via <see cref="ISqlDialect.QuoteIdentifier"/>.</param>
+    /// <returns>The accepted and rejected sets.</returns>
+    /// <exception cref="ArgumentNullException">A required argument is null.</exception>
+    public static SqlCatalogGateResult Apply(
+        IEnumerable<SqlTagDefinition> definitions, SqlCatalog catalog, ISqlDialect dialect)
+    {
+        ArgumentNullException.ThrowIfNull(definitions);
+        ArgumentNullException.ThrowIfNull(catalog);
+        ArgumentNullException.ThrowIfNull(dialect);
+
+        var accepted = new List<SqlTagDefinition>();
+        var rejected = new List<SqlCatalogRejection>();
+
+        foreach (var definition in definitions)
+        {
+            ArgumentNullException.ThrowIfNull(definition);
+            if (TryCanonicalize(definition, catalog, dialect, out var canonical, out var rejection))
+                accepted.Add(canonical!);
+            else
+                rejected.Add(rejection!);
+        }
+
+        return new SqlCatalogGateResult(accepted, rejected);
+    }
+
+    /// <summary>Resolves one definition's identifiers, or explains the first failure.</summary>
+    private static bool TryCanonicalize(
+        SqlTagDefinition definition,
+        SqlCatalog catalog,
+        ISqlDialect dialect,
+        out SqlTagDefinition? canonical,
+        out SqlCatalogRejection? rejection)
+    {
+        canonical = null;
+        rejection = null;
+
+        if (!TryResolveRelation(definition, catalog, dialect, out var schema, out var table, out rejection))
+            return false;
+
+        // Every identifier-bearing field, paired with its name for the rejection message. A field the tag's
+        // model does not use is null and simply skipped — the planner enforces which are required.
+        var resolved = new Dictionary<string, string?>(StringComparer.Ordinal);
+        foreach (var (field, authored) in new (string Field, string? Authored)[]
+                 {
+                     (nameof(SqlTagDefinition.KeyColumn), definition.KeyColumn),
+                     (nameof(SqlTagDefinition.ValueColumn), definition.ValueColumn),
+                     (nameof(SqlTagDefinition.TimestampColumn), definition.TimestampColumn),
+                     (nameof(SqlTagDefinition.ColumnName), definition.ColumnName),
+                     (nameof(SqlTagDefinition.RowSelectorColumn), definition.RowSelectorColumn),
+                     (nameof(SqlTagDefinition.RowSelectorTopByTimestamp), definition.RowSelectorTopByTimestamp),
+                 })
+        {
+            if (string.IsNullOrWhiteSpace(authored))
+            {
+                resolved[field] = authored;
+                continue;
+            }
+
+            if (!IsRenderableIdentifier(authored, dialect))
+            {
+                rejection = new SqlCatalogRejection(definition.Name, field,
+                    $"the authored {field} is not a usable identifier (it is over-long, or contains control " +
+                    "or Unicode format characters); the value is withheld from this message because it " +
+                    "cannot be safely rendered");
+                return false;
+            }
+
+            if (!catalog.TryResolveColumn(schema, table, authored, out var column))
+            {
+                rejection = new SqlCatalogRejection(definition.Name, field,
+                    $"column '{authored}' does not exist on '{schema}.{table}' (or matches more than one " +
+                    "column under a case-sensitive collation)");
+                return false;
+            }
+
+            resolved[field] = column;
+        }
+
+        canonical = definition with
+        {
+            Table = SqlCatalog.QualifiedKey(schema, table),
+            KeyColumn = resolved[nameof(SqlTagDefinition.KeyColumn)],
+            ValueColumn = resolved[nameof(SqlTagDefinition.ValueColumn)],
+            TimestampColumn = resolved[nameof(SqlTagDefinition.TimestampColumn)],
+            ColumnName = resolved[nameof(SqlTagDefinition.ColumnName)],
+            RowSelectorColumn = resolved[nameof(SqlTagDefinition.RowSelectorColumn)],
+            RowSelectorTopByTimestamp = resolved[nameof(SqlTagDefinition.RowSelectorTopByTimestamp)],
+        };
+        return true;
+    }
+
+    /// <summary>Splits and resolves the authored <c>table</c> to a canonical schema + relation.</summary>
+    private static bool TryResolveRelation(
+        SqlTagDefinition definition,
+        SqlCatalog catalog,
+        ISqlDialect dialect,
+        out string schema,
+        out string table,
+        out SqlCatalogRejection? rejection)
+    {
+        schema = string.Empty;
+        table = string.Empty;
+        rejection = null;
+        const string Field = nameof(SqlTagDefinition.Table);
+
+        if (string.IsNullOrWhiteSpace(definition.Table))
+        {
+            rejection = new SqlCatalogRejection(definition.Name, Field,
+                "the tag has no 'table'; author the table or view to read");
+            return false;
+        }
+
+        var parts = definition.Table.Split('.');
+        if (parts.Length > MaxNameParts)
+        {
+            rejection = new SqlCatalogRejection(definition.Name, Field,
+                $"'{definition.Table}' is a {parts.Length}-part name. Only 'table' and 'schema.table' can be " +
+                "validated against this connection's catalog, so a cross-database or linked-server name " +
+                "cannot be allow-listed; expose the data through a view in this database instead");
+            return false;
+        }
+
+        var authoredSchema = parts.Length == MaxNameParts ? parts[0] : null;
+        var authoredTable = parts[^1];
+
+        foreach (var part in parts)
+        {
+            if (IsRenderableIdentifier(part, dialect)) continue;
+            rejection = new SqlCatalogRejection(definition.Name, Field,
+                "the authored table name has a part that is not a usable identifier (empty, over-long, or " +
+                "containing control or Unicode format characters); the value is withheld from this message " +
+                "because it cannot be safely rendered");
+            return false;
+        }
+
+        if (!catalog.TryResolveSchema(authoredSchema, out schema))
+        {
+            rejection = new SqlCatalogRejection(definition.Name, Field,
+                $"schema '{authoredSchema}' does not exist (or matches more than one schema under a " +
+                "case-sensitive collation)");
+            return false;
+        }
+
+        if (!catalog.TryResolveTable(schema, authoredTable, out table))
+        {
+            rejection = new SqlCatalogRejection(definition.Name, Field,
+                $"table or view '{authoredTable}' does not exist in schema '{schema}'" +
+                (authoredSchema is null
+                    ? $" (the connection's default schema — qualify the name as 'schema.{authoredTable}' if it lives elsewhere)"
+                    : string.Empty));
+            return false;
+        }
+
+        return true;
+    }
+
+    /// <summary>
+    ///     True when the dialect's quoting rules accept <paramref name="identifier"/> — i.e. it is safe both to
+    ///     embed in SQL and to render into a log line or an AdminUI label.
+    /// </summary>
+    /// <remarks>
+    ///     Uses <see cref="ISqlDialect.QuoteIdentifier"/> as the charset authority rather than duplicating its
+    ///     rules, so the two can never disagree about what a legal identifier is. The quoted result is
+    ///     discarded: only whether it threw is interesting here.
+    /// </remarks>
+    private static bool IsRenderableIdentifier(string identifier, ISqlDialect dialect)
+    {
+        try
+        {
+            dialect.QuoteIdentifier(identifier);
+            return true;
+        }
+        catch (ArgumentException)
+        {
+            return false;
+        }
+    }
+}

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql/SqlCatalogLoader.cs

@@ -0,0 +1,189 @@
+using System.Data;
+using System.Data.Common;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Sql;
+
+/// <summary>
+///     Loads the <see cref="SqlCatalog"/> slice the authored tags need, over one connection, using only the
+///     dialect's catalog SQL (design §8.1).
+/// </summary>
+/// <remarks>
+///     <para><b>Bounded by what is authored, not by what exists.</b> One query for the schema list, one for
+///     the default schema, then one <see cref="ISqlDialect.ListTablesSql"/> per distinct authored schema and
+///     one <see cref="ISqlDialect.ListColumnsSql"/> per distinct authored relation. A driver polling three
+///     tables issues a handful of round-trips at Initialize and none thereafter; it never enumerates a
+///     warehouse.</para>
+///     <para><b>Every parameter is bound.</b> Authored names reach the catalog queries as
+///     <c>@schema</c>/<c>@table</c> parameters — the same discipline the schema browser follows — so loading
+///     the allow-list cannot itself be an injection vector. No identifier is quoted into text on this path.</para>
+///     <para><b>Failures throw; they do not degrade to an empty catalog.</b> An empty catalog would reject
+///     every tag, which is indistinguishable at the OPC UA surface from a database whose objects were all
+///     dropped. A caller that cannot read the catalog has not learned that the tags are invalid — it has
+///     learned nothing — and must fail its Initialize so the driver retries rather than serving a
+///     confidently-empty address space.</para>
+/// </remarks>
+internal static class SqlCatalogLoader
+{
+    /// <summary>Column alias <see cref="ISqlDialect.ListSchemasSql"/> projects.</summary>
+    private const string SchemaColumn = "TABLE_SCHEMA";
+
+    /// <summary>Column alias <see cref="ISqlDialect.ListTablesSql"/> projects.</summary>
+    private const string TableNameColumn = "TABLE_NAME";
+
+    /// <summary>Column alias <see cref="ISqlDialect.ListColumnsSql"/> projects.</summary>
+    private const string ColumnNameColumn = "COLUMN_NAME";
+
+    /// <summary>
+    ///     Reads the catalog slice covering <paramref name="authoredTables"/>.
+    /// </summary>
+    /// <param name="connection">An <b>already-open</b> connection. Not disposed here; the caller owns it.</param>
+    /// <param name="dialect">Supplies the catalog SQL.</param>
+    /// <param name="authoredTables">The distinct authored <c>table</c> strings, as written in the blobs.</param>
+    /// <param name="commandTimeout">Per-command server-side backstop.</param>
+    /// <param name="cancellationToken">Cancellation token for the operation.</param>
+    /// <returns>The loaded catalog.</returns>
+    /// <exception cref="InvalidOperationException">The connection can see no schemas at all.</exception>
+    internal static async Task<SqlCatalog> LoadAsync(
+        DbConnection connection,
+        ISqlDialect dialect,
+        IReadOnlyCollection<string> authoredTables,
+        TimeSpan commandTimeout,
+        CancellationToken cancellationToken)
+    {
+        var timeoutSeconds = Math.Max(1, (int)Math.Ceiling(commandTimeout.TotalSeconds));
+
+        var schemas = await QueryColumnAsync(
+            connection, dialect.ListSchemasSql, SchemaColumn,
+            static _ => { }, timeoutSeconds, cancellationToken).ConfigureAwait(false);
+
+        // Zero schemas is a permissions or visibility symptom, never a real database. Rejecting every tag on
+        // that basis would report an authoring fault for what is actually a grant problem, and would send the
+        // operator to the wrong system — the same misdiagnosis the driver's health classification avoids.
+        if (schemas.Count == 0)
+            throw new InvalidOperationException(
+                "the catalog returned no schemas at all; the connecting principal most likely cannot read " +
+                "the catalog views, which is a grant problem rather than a tag-authoring one");
+
+        var defaultSchema = await ReadDefaultSchemaAsync(
+            connection, dialect, timeoutSeconds, cancellationToken).ConfigureAwait(false);
+
+        var tablesBySchema = new Dictionary<string, IReadOnlyList<string>>(StringComparer.Ordinal);
+        var columnsByTable = new Dictionary<string, IReadOnlyList<string>>(StringComparer.Ordinal);
+
+        // Resolving here goes through SqlCatalog.TryMatch — the SAME matcher the gate will use — so the
+        // loader and the gate can never disagree about which relation an authored name resolved to. Loading
+        // one table and validating against another would be a silent wrong-column defect.
+        foreach (var authored in authoredTables)
+        {
+            if (string.IsNullOrWhiteSpace(authored)) continue;
+
+            var parts = authored.Split('.');
+            if (parts.Length > 2) continue;   // the gate rejects these by name; nothing to load.
+
+            var authoredTable = parts[^1];
+            string schema;
+            if (parts.Length == 2)
+            {
+                if (!SqlCatalog.TryMatch(schemas, parts[0], out schema)) continue;
+            }
+            else
+            {
+                schema = defaultSchema;
+            }
+
+            if (!tablesBySchema.TryGetValue(schema, out var tables))
+            {
+                tables = await QueryColumnAsync(
+                    connection, dialect.ListTablesSql, TableNameColumn,
+                    command => Bind(command, "@schema", schema),
+                    timeoutSeconds, cancellationToken).ConfigureAwait(false);
+                tablesBySchema[schema] = tables;
+            }
+
+            if (!SqlCatalog.TryMatch(tables, authoredTable, out var table)) continue;
+
+            var key = SqlCatalog.QualifiedKey(schema, table);
+            if (columnsByTable.ContainsKey(key)) continue;
+
+            columnsByTable[key] = await QueryColumnAsync(
+                connection, dialect.ListColumnsSql, ColumnNameColumn,
+                command =>
+                {
+                    Bind(command, "@schema", schema);
+                    Bind(command, "@table", table);
+                },
+                timeoutSeconds, cancellationToken).ConfigureAwait(false);
+        }
+
+        return new SqlCatalog(defaultSchema, schemas, tablesBySchema, columnsByTable);
+    }
+
+    /// <summary>
+    ///     Reads the connection's default schema, falling back to the sole visible schema when the dialect's
+    ///     query answers null/blank.
+    /// </summary>
+    /// <remarks>
+    ///     A null answer is possible (a login with no default schema mapped). Falling back to the single
+    ///     visible schema keeps the common one-schema database working; with several visible schemas there is
+    ///     no defensible guess, so unqualified names simply will not resolve and the gate says so by name.
+    /// </remarks>
+    private static async Task<string> ReadDefaultSchemaAsync(
+        DbConnection connection, ISqlDialect dialect, int timeoutSeconds, CancellationToken cancellationToken)
+    {
+        var command = connection.CreateCommand();
+        await using (command.ConfigureAwait(false))
+        {
+            command.CommandText = dialect.DefaultSchemaSql;
+            command.CommandTimeout = timeoutSeconds;
+            var value = await command.ExecuteScalarAsync(cancellationToken).ConfigureAwait(false);
+            var schema = value is null or DBNull ? null : value.ToString();
+            return string.IsNullOrWhiteSpace(schema) ? string.Empty : schema;
+        }
+    }
+
+    /// <summary>Runs one catalog query and projects a single string column from every row.</summary>
+    private static async Task<IReadOnlyList<string>> QueryColumnAsync(
+        DbConnection connection,
+        string sql,
+        string columnName,
+        Action<DbCommand> bind,
+        int timeoutSeconds,
+        CancellationToken cancellationToken)
+    {
+        var results = new List<string>();
+
+        var command = connection.CreateCommand();
+        await using (command.ConfigureAwait(false))
+        {
+            command.CommandText = sql;
+            command.CommandTimeout = timeoutSeconds;
+            bind(command);
+
+            var reader = await command
+                .ExecuteReaderAsync(CommandBehavior.SingleResult, cancellationToken).ConfigureAwait(false);
+            await using (reader.ConfigureAwait(false))
+            {
+                var ordinal = -1;
+                while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
+                {
+                    if (ordinal < 0) ordinal = reader.GetOrdinal(columnName);
+                    if (reader.IsDBNull(ordinal)) continue;
+                    var value = reader.GetValue(ordinal)?.ToString();
+                    if (!string.IsNullOrWhiteSpace(value)) results.Add(value);
+                }
+            }
+        }
+
+        return results;
+    }
+
+    /// <summary>Binds one catalog-query parameter — the only way an authored name reaches the database here.</summary>
+    private static void Bind(DbCommand command, string name, string value)
+    {
+        var parameter = command.CreateParameter();
+        parameter.ParameterName = name;
+        parameter.DbType = DbType.String;
+        parameter.Value = value;
+        command.Parameters.Add(parameter);
+    }
+}

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql/SqlDriver.cs

@@ -29,14 +29,12 @@ public sealed class SqlDriver
     : IDriver, ITagDiscovery, IReadable, ISubscribable, IHostConnectivityProbe, IAsyncDisposable
 {
     /// <summary>
-    ///     The driver-type string this driver registers under.
-    ///     <para><b>Deliberately a local constant, not <c>DriverTypeNames.Sql</c>.</b>
-    ///     <c>DriverTypeNamesGuardTests</c> asserts bidirectional parity between the constants and the
-    ///     driver factories actually registered in the process, so the constant may only be added in the
-    ///     same change that wires the factory (this task ships no factory — see the plan's Task 11, which
-    ///     adds <c>DriverTypeNames.Sql</c> and repoints this constant at it).</para>
+    ///     The driver-type string this driver registers under — <see cref="DriverTypeNames.Sql"/>, the single
+    ///     source of truth the deploy pipeline stores in <c>DriverInstance.DriverType</c> and every dispatch
+    ///     map keys by. Chained off the shared constant (Task 11 wired the factory + probe, so
+    ///     <c>DriverTypeNamesGuardTests</c>' bidirectional-parity check is satisfied).
     /// </summary>
-    public const string DriverTypeName = "Sql";
+    public const string DriverTypeName = DriverTypeNames.Sql;
 
     /// <summary>Shown for a connection string that names no recognisable server.</summary>
     private const string UnknownEndpoint = "(unknown sql endpoint)";
@@ -76,7 +74,23 @@ public sealed class SqlDriver
     private IReadOnlyDictionary<string, SqlTagDefinition> _tagsByRawPath =
         new Dictionary<string, SqlTagDefinition>(StringComparer.Ordinal);
 
-    /// <summary>Resolves a read/subscribe RawPath to its authored definition — a single table hit, or a miss.</summary>
+    /// <summary>
+    ///     The subset of <see cref="_tagsByRawPath"/> that survived the design §8.1 catalog gate, with every
+    ///     identifier rewritten to the catalog's own spelling. <b>This — not the authored table — is what a
+    ///     read or a poll resolves against</b>, so an identifier that never appeared in the catalog can never
+    ///     reach a query.
+    ///     <para><b>Why the two tables are separate.</b> A tag the gate rejected must still <em>exist</em> as a
+    ///     node: §8.1's specified outcome is that it publishes
+    ///     <see cref="SqlStatusCodes.BadNodeIdUnknown"/>, and a status code can only be published by a node
+    ///     that is there. Dropping rejected tags from the authored table too would delete the node instead,
+    ///     turning a diagnosable Bad quality into a silently missing address-space entry — a strictly worse
+    ///     failure for the operator trying to find their typo.</para>
+    ///     <para>Swapped atomically, for the same reason the authored table is.</para>
+    /// </summary>
+    private IReadOnlyDictionary<string, SqlTagDefinition> _polledByRawPath =
+        new Dictionary<string, SqlTagDefinition>(StringComparer.Ordinal);
+
+    /// <summary>Resolves a read/subscribe RawPath to its <b>catalog-validated</b> definition, or a miss.</summary>
     private readonly EquipmentTagRefResolver<SqlTagDefinition> _resolver;
 
     /// <summary>
@@ -184,8 +198,18 @@ public sealed class SqlDriver
     /// <summary>The current authored-tag snapshot. Read through a barrier — <see cref="BuildTagTable"/> swaps it.</summary>
     private IReadOnlyDictionary<string, SqlTagDefinition> Tags => Volatile.Read(ref _tagsByRawPath);
 
-    /// <summary>The resolver's lookup: RawPath → authored definition, or null on a miss.</summary>
-    private SqlTagDefinition? Lookup(string rawPath) => Tags.GetValueOrDefault(rawPath);
+    /// <summary>
+    ///     The catalog-validated snapshot. Read through a barrier — <see cref="ApplyCatalogGateAsync"/> swaps it.
+    /// </summary>
+    private IReadOnlyDictionary<string, SqlTagDefinition> PolledTags => Volatile.Read(ref _polledByRawPath);
+
+    /// <summary>
+    ///     The resolver's lookup: RawPath → <b>catalog-validated</b> definition, or null on a miss.
+    ///     <para>Deliberately reads <see cref="PolledTags"/> rather than <see cref="Tags"/>: a tag the gate
+    ///     rejected must miss here so the reader publishes
+    ///     <see cref="SqlStatusCodes.BadNodeIdUnknown"/>, exactly as design §8.1 specifies.</para>
+    /// </summary>
+    private SqlTagDefinition? Lookup(string rawPath) => PolledTags.GetValueOrDefault(rawPath);
 
     // ---- IDriver lifecycle ----
 
@@ -198,11 +222,16 @@ public sealed class SqlDriver
     ///     I/O, and on failure this method records <see cref="DriverState.Faulted"/> <b>and rethrows</b> —
     ///     <c>DriverInstanceActor</c> reads a throw as InitializeFailed and lands in Reconnecting with its
     ///     retry timer running, which is exactly the recovery a database that is merely down needs.</para>
+    ///     <para>The liveness check is then followed by the design §8.1 <b>catalog gate</b>
+    ///     (<see cref="ApplyCatalogGateAsync"/>), which is the second and last piece of I/O. It runs after
+    ///     liveness because it needs a working connection, and before the driver reports Healthy because the
+    ///     tag table it publishes must be the validated one — a poll must never see an unvalidated
+    ///     identifier.</para>
     /// </summary>
     /// <param name="driverConfigJson">The driver configuration JSON (unused; see remarks).</param>
     /// <param name="cancellationToken">Cancellation token for the operation.</param>
     /// <returns>A task that represents the asynchronous operation.</returns>
-    /// <exception cref="InvalidOperationException">The database could not be reached.</exception>
+    /// <exception cref="InvalidOperationException">The database could not be reached, or its catalog could not be read.</exception>
     public async Task InitializeAsync(string driverConfigJson, CancellationToken cancellationToken)
     {
         WriteHealth(new DriverHealth(DriverState.Initializing, null, null));
@@ -236,6 +265,36 @@ public sealed class SqlDriver
             throw new InvalidOperationException(message, ex);
         }
 
+        // Separate try from liveness so the operator surface names the stage that actually failed: "could
+        // not reach the database" and "reached it but could not read its catalog" send an operator to
+        // different places, and the second is usually a GRANT rather than an outage.
+        try
+        {
+            await ApplyCatalogGateAsync(cancellationToken).ConfigureAwait(false);
+        }
+        catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
+        {
+            WriteHealth(new DriverHealth(DriverState.Unknown, null, null));
+            throw;
+        }
+        catch (Exception ex)
+        {
+            // Same discipline as above: exception TYPE only on the operator surface, full exception to the
+            // log sink. A catalog read that fails is NOT evidence the tags are wrong — it is the absence of
+            // evidence — so this faults the driver (and retries) rather than rejecting every tag and serving
+            // a confidently-empty address space.
+            var message =
+                $"Sql driver '{_driverInstanceId}' reached {Endpoint} but could not read its catalog to " +
+                $"validate authored tables/columns: {ex.GetType().Name}. Check that the connecting principal " +
+                "can read the catalog views.";
+            _logger.LogError(ex,
+                "Sql driver {DriverInstanceId} catalog validation against {Endpoint} failed.",
+                _driverInstanceId, Endpoint);
+            WriteHealth(new DriverHealth(DriverState.Faulted, null, message));
+            TransitionHostTo(HostState.Stopped);
+            throw new InvalidOperationException(message, ex);
+        }
+
         WriteHealth(new DriverHealth(DriverState.Healthy, DateTime.UtcNow, null));
         TransitionHostTo(HostState.Running);
         _logger.LogInformation(
@@ -492,15 +551,17 @@ public sealed class SqlDriver
         // A subscribed-read outage surfaces as a DbException the reader threw, which ReadAsync has ALREADY
         // classified — good, endpoint-bearing LastError + host Stopped — before rethrowing. The poll engine
         // then routes that same exception here. Re-degrading would overwrite the good LastError with a worse,
-        // guidance-free one (and, for a provider whose text echoes credentials, re-open the C1 leak) and log
-        // the outage a second time. So skip the connection class ReadAsync owns; the only exceptions that
-        // reach past this guard are the engine's own contract-violation throws — an InvalidOperationException
-        // carrying no provider text — which nothing else classifies.
+        // guidance-free one and log the outage a second time, so skip the connection class ReadAsync owns.
         if (ex is DbException) return;
 
+        // Whatever reaches here — an engine contract-violation, or a non-DbException the provider raised
+        // (e.g. an ArgumentException from a malformed connection string, which the parser echoes with
+        // credential fragments) — the operator surface carries only the exception TYPE, never ex.Message.
+        // The full exception, with its text, still reaches the log SINK via the exception parameter. This is
+        // the same unconditional rule InitializeAsync/ReadAsync follow; do not weaken it to a type check.
         _logger.LogWarning(ex, "Sql poll failed. Driver={DriverInstanceId} Endpoint={Endpoint}",
             _driverInstanceId, Endpoint);
-        Degrade(ex.Message);
+        Degrade($"Sql driver '{_driverInstanceId}' poll failed: {ex.GetType().Name}.");
     }
 
     /// <summary>
@@ -594,6 +655,94 @@ public sealed class SqlDriver
         }
 
         Volatile.Write(ref _tagsByRawPath, table);
+
+        // Nothing is pollable until the catalog gate has validated it. Clearing here (rather than leaving a
+        // previous generation's validated table in place) means a Reinitialize whose gate then fails cannot
+        // keep polling the OLD identifiers against a database whose schema may be exactly what changed.
+        Volatile.Write(ref _polledByRawPath, new Dictionary<string, SqlTagDefinition>(StringComparer.Ordinal));
+    }
+
+    // ---- catalog gate (design §8.1) ----
+
+    /// <summary>
+    ///     Validates every authored identifier against the live catalog and republishes the tag table with
+    ///     catalog spellings, dropping the tags that do not resolve (design §8.1).
+    /// </summary>
+    /// <remarks>
+    ///     <para><b>Why this must run before the driver reports Healthy.</b> The table this swaps in is what
+    ///     every poll resolves against. Running it later — or in the background — would leave a window in
+    ///     which an unvalidated identifier could be quoted into a query, which is the entire hole the gate
+    ///     exists to close.</para>
+    ///     <para><b>A dropped tag is not a driver fault.</b> It disappears from the table, so its RawPath
+    ///     resolves to nothing and it publishes <see cref="SqlStatusCodes.BadNodeIdUnknown"/> — one operator
+    ///     typo must not stop the other tags on that database, the same rule
+    ///     <see cref="BuildTagTable"/> follows for a malformed blob. Each drop is logged at Warning with the
+    ///     tag, the field and the reason, because a node that silently goes Bad with nothing in the log is
+    ///     unsupportable.</para>
+    ///     <para><b>No tags ⇒ no I/O.</b> A driver with nothing authored has nothing to validate, and issuing
+    ///     catalog queries to prove that would be a round-trip that can only fail.</para>
+    ///     <para>Bounded by the same wall-clock discipline as the liveness check (R2-01 / STAB-14): the work
+    ///     runs on the thread pool so a provider implementing the async path synchronously blocks a pool
+    ///     thread rather than wedging Initialize forever with no retry.</para>
+    /// </remarks>
+    /// <param name="cancellationToken">The caller's token.</param>
+    /// <returns>A task that completes when the tag table has been validated and republished.</returns>
+    private async Task ApplyCatalogGateAsync(CancellationToken cancellationToken)
+    {
+        var authored = Tags;
+        if (authored.Count == 0) return;
+
+        var tables = authored.Values
+            .Select(definition => definition.Table)
+            .Where(table => !string.IsNullOrWhiteSpace(table))
+            .Distinct(StringComparer.OrdinalIgnoreCase)
+            .ToArray();
+
+        var catalog = await RunBoundedAsync(
+            token => LoadCatalogAsync(tables, token),
+            _options.OperationTimeout,
+            "the catalog queries did not return",
+            cancellationToken).ConfigureAwait(false);
+
+        var result = SqlCatalogGate.Apply(authored.Values, catalog, _dialect);
+
+        foreach (var rejection in result.Rejected)
+        {
+            _logger.LogWarning(
+                "Sql tag '{Tag}' rejected by the catalog gate: {Field} — {Reason}. It will publish "
+                + "BadNodeIdUnknown until the tag or the database is corrected. Driver={DriverInstanceId}",
+                rejection.RawPath, rejection.Field, rejection.Reason, _driverInstanceId);
+        }
+
+        var validated = new Dictionary<string, SqlTagDefinition>(result.Accepted.Count, StringComparer.Ordinal);
+        foreach (var definition in result.Accepted) validated[definition.Name] = definition;
+
+        // Only the POLLED table is replaced. The authored table is left intact so every authored tag keeps
+        // its node and a rejected one publishes BadNodeIdUnknown rather than vanishing (see _polledByRawPath).
+        Volatile.Write(ref _polledByRawPath, validated);
+
+        _logger.LogInformation(
+            "Sql driver {DriverInstanceId} catalog gate accepted {Accepted} of {Total} authored tag(s) "
+            + "across {Tables} table(s) on {Endpoint}.",
+            _driverInstanceId, result.Accepted.Count, authored.Count, tables.Length, Endpoint);
+    }
+
+    /// <summary>Opens one connection and reads the catalog slice the authored tables need.</summary>
+    private async Task<SqlCatalog> LoadCatalogAsync(
+        IReadOnlyCollection<string> authoredTables, CancellationToken cancellationToken)
+    {
+        var connection = _factory.CreateConnection()
+                         ?? throw new InvalidOperationException(
+                             $"the {_dialect.Provider} provider factory returned no connection.");
+
+        await using (connection.ConfigureAwait(false))
+        {
+            connection.ConnectionString = _connectionString;
+            await connection.OpenAsync(cancellationToken).ConfigureAwait(false);
+            return await SqlCatalogLoader
+                .LoadAsync(connection, _dialect, authoredTables, _options.CommandTimeout, cancellationToken)
+                .ConfigureAwait(false);
+        }
     }
 
     // ---- liveness ----
@@ -611,18 +760,50 @@ public sealed class SqlDriver
     /// </summary>
     /// <param name="cancellationToken">The caller's token.</param>
     /// <returns>A task that completes when the database has answered.</returns>
-    private async Task VerifyLivenessAsync(CancellationToken cancellationToken)
+    private Task VerifyLivenessAsync(CancellationToken cancellationToken) =>
+        RunBoundedAsync(
+            async token => { await PingAsync(token).ConfigureAwait(false); return true; },
+            _options.CommandTimeout,
+            "the liveness statement did not return",
+            cancellationToken);
+
+    /// <summary>
+    ///     Runs <paramref name="work"/> under a hard wall-clock <paramref name="budget"/>, on the thread pool,
+    ///     converting a breach into a <see cref="TimeoutException"/> worded from <paramref name="what"/>.
+    /// </summary>
+    /// <remarks>
+    ///     <para>The R2-01 / STAB-14 shape, shared by the two pieces of I/O Initialize performs. It exists
+    ///     because a token is not a deadline: some ADO.NET providers implement the async path synchronously,
+    ///     and a wedged socket can hang <em>inside</em> the provider's own cancellation handshake. Without an
+    ///     independent wall clock, <c>DriverInstanceActor</c>'s init task would never complete and the driver
+    ///     would sit in Connecting forever with no retry — the exact frozen-peer wedge the S7 driver shipped.</para>
+    ///     <para>Both the linked CTS deadline and an outer <see cref="TaskExtensions"/> wait are used, because
+    ///     each covers a case the other does not: the CTS handles a provider that <em>does</em> honour
+    ///     cancellation, and the outer wait handles one that does not. An abandoned attempt keeps ownership of
+    ///     its own connection and disposes it; <see cref="Detach"/> observes its eventual fault.</para>
+    /// </remarks>
+    /// <typeparam name="T">The work's result type.</typeparam>
+    /// <param name="work">The operation to bound. Receives the deadline-linked token.</param>
+    /// <param name="budget">The wall-clock allowance.</param>
+    /// <param name="what">Sentence fragment naming the operation, e.g. "the catalog queries did not return".</param>
+    /// <param name="cancellationToken">The caller's token.</param>
+    /// <returns>The work's result.</returns>
+    /// <exception cref="TimeoutException">The budget elapsed first.</exception>
+    private static async Task<T> RunBoundedAsync<T>(
+        Func<CancellationToken, Task<T>> work,
+        TimeSpan budget,
+        string what,
+        CancellationToken cancellationToken)
     {
-        var budget = _options.CommandTimeout;
         var deadline = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
-        Task work;
+        Task<T> running;
         try
         {
             deadline.CancelAfter(budget);
-            work = Task.Run(
+            running = Task.Run(
                 async () =>
                 {
-                    try { await PingAsync(deadline.Token).ConfigureAwait(false); }
+                    try { return await work(deadline.Token).ConfigureAwait(false); }
                     finally { deadline.Dispose(); }
                 },
                 CancellationToken.None);
@@ -636,20 +817,18 @@ public sealed class SqlDriver
 
         try
         {
-            await work.WaitAsync(budget, cancellationToken).ConfigureAwait(false);
+            return await running.WaitAsync(budget, cancellationToken).ConfigureAwait(false);
         }
         catch (TimeoutException)
         {
-            Detach(work);
-            throw new TimeoutException(
-                $"the liveness statement did not return within {(int)budget.TotalMilliseconds} ms.");
+            Detach(running);
+            throw new TimeoutException($"{what} within {(int)budget.TotalMilliseconds} ms.");
         }
         catch (OperationCanceledException) when (!cancellationToken.IsCancellationRequested)
         {
             // Our deadline fired and the provider DID honour the linked token.
-            Detach(work);
-            throw new TimeoutException(
-                $"the liveness statement did not return within {(int)budget.TotalMilliseconds} ms.");
+            Detach(running);
+            throw new TimeoutException($"{what} within {(int)budget.TotalMilliseconds} ms.");
         }
     }
 
@@ -752,6 +931,7 @@ public sealed class SqlDriver
     {
         await _poll.DisposeAsync().ConfigureAwait(false);
         Volatile.Write(ref _tagsByRawPath, new Dictionary<string, SqlTagDefinition>(StringComparer.Ordinal));
+        Volatile.Write(ref _polledByRawPath, new Dictionary<string, SqlTagDefinition>(StringComparer.Ordinal));
         _resolver.Clear();   // no-op in v3 (the resolver reads the live table by closure); kept for symmetry
     }
 }

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql/SqlDriverFactoryExtensions.cs

@@ -29,12 +29,9 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.Sql;
 public static class SqlDriverFactoryExtensions
 {
     /// <summary>
-    ///     The driver-type string this factory registers under.
-    ///     <para>Chained off <see cref="SqlDriver.DriverTypeName"/> rather than <c>DriverTypeNames.Sql</c>:
-    ///     <c>DriverTypeNamesGuardTests</c> asserts bidirectional parity between the shared constants and the
-    ///     factories actually registered in the process, so the constant may only be added in the change that
-    ///     also wires this factory into the Host (the plan's Task 11, which repoints both at
-    ///     <c>DriverTypeNames.Sql</c>).</para>
+    ///     The driver-type string this factory registers under — chained off
+    ///     <see cref="SqlDriver.DriverTypeName"/>, which is
+    ///     <see cref="ZB.MOM.WW.OtOpcUa.Core.Abstractions.DriverTypeNames.Sql"/>.
     /// </summary>
     public const string DriverTypeName = SqlDriver.DriverTypeName;
 

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql/SqlServerDialect.cs

@@ -44,6 +44,12 @@ public sealed class SqlServerDialect : ISqlDialect
     public string ListSchemasSql =>
         "SELECT DISTINCT TABLE_SCHEMA FROM INFORMATION_SCHEMA.TABLES ORDER BY TABLE_SCHEMA";
 
+    /// <summary>
+    ///     <c>SCHEMA_NAME()</c> with no argument returns the calling principal's default schema — the one an
+    ///     unqualified object name resolves in, which is precisely the question the catalog gate asks.
+    /// </summary>
+    public string DefaultSchemaSql => "SELECT SCHEMA_NAME()";
+
     /// <inheritdoc/>
     public string ListTablesSql =>
         "SELECT TABLE_NAME, TABLE_TYPE FROM INFORMATION_SCHEMA.TABLES " +
@@ -70,9 +76,11 @@ public sealed class SqlServerDialect : ISqlDialect
     ///     control-character rule.</para>
     ///     <para>The rejection messages deliberately do <b>not</b> echo the offending value — it is untrusted
     ///     input and this exception's text reaches the driver log.</para>
-    ///     <para><b>This is currently the only defence, not a backstop.</b> Design §8.1 specifies that an
-    ///     identifier is validated against the live catalog before reaching here; that gate is not implemented
-    ///     yet, so an authored <c>TagConfig</c> table/column arrives unfiltered.</para>
+    ///     <para><b>This is a backstop, not the only defence.</b> Design §8.1's catalog gate
+    ///     (<see cref="SqlCatalogGate"/>) resolves an authored table/column against the live catalog at
+    ///     Initialize and substitutes the catalog's own spelling, so on the poll path the value arriving here
+    ///     is a string read back out of the catalog. The rules below still run — the gate uses them as its own
+    ///     charset filter, and they must hold for any future caller that has no catalog to check against.</para>
     /// </remarks>
     /// <param name="ident">The bare, unquoted identifier part.</param>
     /// <returns>The bracket-quoted identifier.</returns>

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT/TwinCATStatusMapper.cs

@@ -19,9 +19,9 @@ public static class TwinCATStatusMapper
     public const uint BadDeviceFailure      = 0x808B0000u;
     public const uint BadCommunicationError = 0x80050000u;
     public const uint BadTimeout            = 0x800A0000u;
-    public const uint BadTypeMismatch       = 0x80730000u;
-    public const uint BadOutOfService       = 0x80BE0000u;
-    public const uint BadInvalidState       = 0x80350000u;
+    public const uint BadTypeMismatch       = 0x80740000u;
+    public const uint BadOutOfService       = 0x808D0000u;
+    public const uint BadInvalidState       = 0x80AF0000u;
 
     // ---- AdsErrorCode numeric values (confirmed from Beckhoff.TwinCAT.Ads 7.0.172) ----
 

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Drivers/DriverConfigModal.razor

@@ -57,6 +57,9 @@
                             case DriverTypeNames.Galaxy:
                                 <GalaxyDriverForm @bind-DriverConfigJson="_driverConfigJson" @bind-ResilienceConfig="_resilienceConfig" />
                                 break;
+                            case DriverTypeNames.Sql:
+                                <SqlDriverForm @bind-DriverConfigJson="_driverConfigJson" @bind-ResilienceConfig="_resilienceConfig" />
+                                break;
                             default:
                                 <div class="alert alert-warning">No typed config form for driver type <span class="mono">@_driverType</span>.</div>
                                 break;

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Drivers/DriverIdentitySection.razor

@@ -36,6 +36,7 @@
                         <option value="Focas">Focas</option>
                         <option value="OpcUaClient">OpcUaClient</option>
                         <option value="GalaxyMxGateway">Galaxy</option>
+                        <option value="Sql">Sql</option>
                     </InputSelect>
                     <div class="form-text">Cannot be changed after creation — drives the actor type that owns this instance.</div>
                 </div>

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Drivers/Forms/SqlDriverForm.razor

@@ -0,0 +1,198 @@
+@* Embeddable read-only Sql driver (connection/dialect) config form body. There is NO per-device
+   endpoint — the whole database connection is named indirectly by ConnectionStringRef (an env-var name,
+   resolved at Initialize), so no connection string is ever authored into the config. Hosted by
+   DriverConfigModal. Exposes GetConfigJson() for the parent to pull at save time and fires
+   DriverConfigJsonChanged for @bind support. Enums serialize by NAME (JsonStringEnumConverter) so the
+   factory's string-typed deserialize accepts them. *@
+@using System.Text.Json
+@using System.Text.Json.Nodes
+@using System.Text.Json.Serialization
+@using ZB.MOM.WW.OtOpcUa.AdminUI.Components.Shared.Drivers
+@using ZB.MOM.WW.OtOpcUa.Driver.Sql.Contracts
+
+@* Connection *@
+<section class="panel rise mt-3" style="animation-delay:.06s">
+    <div class="panel-head">Database connection</div>
+    <div style="padding:1rem">
+        <div class="row g-3">
+            <div class="col-md-4">
+                <label class="form-label">Provider</label>
+                <InputSelect @bind-Value="_form.Provider" @bind-Value:after="EmitAsync" class="form-select form-select-sm">
+                    @* v1 constructs only SqlServer; the other SqlProvider members are reserved (P2). *@
+                    <option value="@SqlProvider.SqlServer">@SqlProvider.SqlServer</option>
+                </InputSelect>
+                <div class="form-text">Only Microsoft SQL Server is supported in v1.</div>
+            </div>
+            <div class="col-md-8">
+                <label class="form-label">Connection string ref <span class="text-danger">*</span></label>
+                <InputText @bind-Value="_form.ConnectionStringRef" @bind-Value:after="EmitAsync" class="form-control form-control-sm mono"
+                           placeholder="MesStaging" />
+                <div class="form-text">
+                    Name of the <code>Sql__ConnectionStrings__&lt;ref&gt;</code> env var set on the driver + AdminUI hosts —
+                    <strong>not</strong> a connection string. The credential is resolved at startup and never stored in the config.
+                </div>
+                @if (string.IsNullOrWhiteSpace(_form.ConnectionStringRef))
+                {
+                    <div class="text-danger small mt-1">Connection string ref is required.</div>
+                }
+            </div>
+        </div>
+    </div>
+</section>
+
+@* Polling / timeouts *@
+<section class="panel rise mt-3" style="animation-delay:.08s">
+    <div class="panel-head">Polling &amp; timeouts</div>
+    <div style="padding:1rem">
+        <div class="row g-3">
+            <div class="col-md-3">
+                <label class="form-label">Default poll interval (s)</label>
+                <InputNumber @bind-Value="_form.DefaultPollIntervalSeconds" @bind-Value:after="EmitAsync" class="form-control form-control-sm" />
+                <div class="form-text">Blank = factory default. Applied to groups without their own interval.</div>
+            </div>
+            <div class="col-md-3">
+                <label class="form-label">Operation timeout (s)</label>
+                <InputNumber @bind-Value="_form.OperationTimeoutSeconds" @bind-Value:after="EmitAsync" class="form-control form-control-sm" />
+                <div class="form-text">Client-side per-query deadline. Should exceed the command timeout.</div>
+            </div>
+            <div class="col-md-3">
+                <label class="form-label">Command timeout (s)</label>
+                <InputNumber @bind-Value="_form.CommandTimeoutSeconds" @bind-Value:after="EmitAsync" class="form-control form-control-sm" />
+                <div class="form-text">ADO.NET server-side CommandTimeout backstop.</div>
+            </div>
+            <div class="col-md-3">
+                <label class="form-label">Max concurrent groups</label>
+                <InputNumber @bind-Value="_form.MaxConcurrentGroups" @bind-Value:after="EmitAsync" class="form-control form-control-sm" />
+                <div class="form-text">Blank = factory default. Caps concurrent group queries (pool guard).</div>
+            </div>
+        </div>
+    </div>
+</section>
+
+@* Value handling *@
+<section class="panel rise mt-3" style="animation-delay:.10s">
+    <div class="panel-head">Value handling</div>
+    <div style="padding:1rem">
+        <div class="row g-3">
+            <div class="col-md-4">
+                <div class="form-check form-switch mt-2">
+                    <InputCheckbox @bind-Value="_form.NullIsBad" @bind-Value:after="EmitAsync" class="form-check-input" id="sqlNullIsBad" />
+                    <label class="form-check-label" for="sqlNullIsBad">NULL cell publishes Bad</label>
+                </div>
+                <div class="form-text mt-0">Unchecked = factory default (a NULL cell publishes Uncertain).</div>
+            </div>
+            <div class="col-md-4">
+                <div class="form-check form-switch mt-2">
+                    <input type="checkbox" class="form-check-input" id="sqlAllowWrites" disabled checked="false" />
+                    <label class="form-check-label" for="sqlAllowWrites">Allow writes</label>
+                </div>
+                <div class="form-text mt-0">
+                    <span class="badge bg-secondary">Read-only</span> v1 does not implement writes — this flag is inert and is not authored.
+                </div>
+            </div>
+        </div>
+    </div>
+</section>
+
+<DriverResilienceSection ResilienceConfig="@ResilienceConfig" ResilienceConfigChanged="OnResilienceChanged" />
+
+@code {
+    /// <summary>The driver-level DriverConfig JSON (connection/dialect; there is no device endpoint).</summary>
+    [Parameter] public string DriverConfigJson { get; set; } = "{}";
+    /// <summary>Fired (camelCase-serialized) whenever a field changes — enables @bind-DriverConfigJson.</summary>
+    [Parameter] public EventCallback<string> DriverConfigJsonChanged { get; set; }
+    /// <summary>The per-instance resilience-pipeline overrides JSON, or null.</summary>
+    [Parameter] public string? ResilienceConfig { get; set; }
+    /// <summary>Fired when the resilience overrides change.</summary>
+    [Parameter] public EventCallback<string?> ResilienceConfigChanged { get; set; }
+
+    // camelCase + string enums + omit-nulls, matching the factory's JsonStringEnumConverter deserialize.
+    // WhenWritingNull keeps absent optionals out of the blob (absent ⇒ the factory applies its default) and
+    // drops the composer-owned rawTags (never authored here).
+    private static readonly JsonSerializerOptions _jsonOpts = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        UnmappedMemberHandling = JsonUnmappedMemberHandling.Skip,
+        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
+        WriteIndented = false,
+        Converters = { new JsonStringEnumConverter() },
+    };
+
+    private FormModel _form = new();
+    private string? _lastParsed;
+
+    protected override void OnParametersSet()
+    {
+        // Re-parse only when the inbound value actually changed (don't clobber in-progress edits).
+        if (!string.Equals(_lastParsed, DriverConfigJson, StringComparison.Ordinal))
+        {
+            var dto = TryDeserialize(DriverConfigJson) ?? new SqlDriverConfigDto();
+            _form = FormModel.FromDto(dto);
+            _lastParsed = DriverConfigJson;
+        }
+    }
+
+    /// <summary>Serializes the current connection/dialect config to camelCase JSON with enums as NAME strings.
+    /// rawTags is never emitted (the composer adds it at deploy); allowWrites is never emitted (v1 read-only).</summary>
+    public string GetConfigJson() => JsonSerializer.Serialize(_form.ToDto(), _jsonOpts);
+
+    private async Task EmitAsync()
+    {
+        var json = GetConfigJson();
+        _lastParsed = json;
+        await DriverConfigJsonChanged.InvokeAsync(json);
+    }
+
+    private async Task OnResilienceChanged(string? r)
+    {
+        ResilienceConfig = r;
+        await ResilienceConfigChanged.InvokeAsync(r);
+    }
+
+    private static SqlDriverConfigDto? TryDeserialize(string json)
+    {
+        try { return JsonSerializer.Deserialize<SqlDriverConfigDto>(json, _jsonOpts); }
+        catch { return null; }
+    }
+
+    /// <summary>Flat mutable mirror of the driver-level fields of <see cref="SqlDriverConfigDto"/>. TimeSpans are
+    /// edited as nullable whole-second ints (blank ⇒ null ⇒ the factory default). rawTags + allowWrites are not
+    /// mirrored — the composer owns rawTags and v1 is read-only.</summary>
+    public sealed class FormModel
+    {
+        public SqlProvider Provider { get; set; } = SqlProvider.SqlServer;
+        public string? ConnectionStringRef { get; set; }
+        public int? DefaultPollIntervalSeconds { get; set; }
+        public int? OperationTimeoutSeconds { get; set; }
+        public int? CommandTimeoutSeconds { get; set; }
+        public int? MaxConcurrentGroups { get; set; }
+        public bool NullIsBad { get; set; }
+
+        public static FormModel FromDto(SqlDriverConfigDto d) => new()
+        {
+            Provider = d.Provider,
+            ConnectionStringRef = d.ConnectionStringRef,
+            DefaultPollIntervalSeconds = ToSeconds(d.DefaultPollInterval),
+            OperationTimeoutSeconds = ToSeconds(d.OperationTimeout),
+            CommandTimeoutSeconds = ToSeconds(d.CommandTimeout),
+            MaxConcurrentGroups = d.MaxConcurrentGroups,
+            NullIsBad = d.NullIsBad ?? false,
+        };
+
+        public SqlDriverConfigDto ToDto() => new()
+        {
+            Provider = Provider,
+            ConnectionStringRef = string.IsNullOrWhiteSpace(ConnectionStringRef) ? null : ConnectionStringRef.Trim(),
+            DefaultPollInterval = ToTimeSpan(DefaultPollIntervalSeconds),
+            OperationTimeout = ToTimeSpan(OperationTimeoutSeconds),
+            CommandTimeout = ToTimeSpan(CommandTimeoutSeconds),
+            MaxConcurrentGroups = MaxConcurrentGroups,
+            // Emit nullIsBad only when true; unchecked ⇒ null ⇒ the factory default (Uncertain). allowWrites
+            // and rawTags are deliberately left null so they are omitted from the authored blob.
+            NullIsBad = NullIsBad ? true : null,
+        };
+
+        private static int? ToSeconds(TimeSpan? ts) => ts.HasValue ? (int)ts.Value.TotalSeconds : null;
+        private static TimeSpan? ToTimeSpan(int? secs) => secs.HasValue ? TimeSpan.FromSeconds(secs.Value) : null;
+    }
+}

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Raw/RawDriverTypeDialog.razor

@@ -68,6 +68,7 @@
         ("FOCAS", DriverTypeNames.FOCAS),
         ("OpcUaClient", DriverTypeNames.OpcUaClient),
         ("Galaxy", DriverTypeNames.Galaxy),
+        ("Sql", DriverTypeNames.Sql),
         ("Calculation", "Calculation"),
     ];
 

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/TagEditors/SqlTagConfigEditor.razor

@@ -1,12 +1,90 @@
-@* Typed TagConfig editor for the read-only Sql driver. MINIMAL PLACEHOLDER (Task 19) — this shell only
-   wires the standard editor parameter contract and round-trips the config through SqlTagConfigModel so no
-   edit is lost while the full UI is pending. Task 20 replaces the body with the model/table/column fields
-   (KeyValue vs WideRow row-selector). Dispatched from the TagModal via TagConfigEditorMap, so it takes the
-   same (ConfigJson/ConfigJsonChanged/DriverType/GetDriverConfigJson) parameter shape every typed editor
-   takes; DriverType/GetDriverConfigJson are accepted for dispatch uniformity. *@
+@* Typed TagConfig editor for the read-only Sql driver. Thin shell over SqlTagConfigModel: every field edit
+   goes model → ToJson → ConfigJsonChanged (the model is the single source of the blob shape + enum-name
+   serialisation; never hand-composed here). The Model dropdown (KeyValue/WideRow) shows the matching field
+   group; the "Build address" picker is the ASSISTED path — every field is also hand-editable. Dispatched
+   from the TagModal via TagConfigEditorMap with the same (ConfigJson/ConfigJsonChanged/DriverType/
+   GetDriverConfigJson) parameter shape every typed editor takes; validation is surfaced centrally by
+   TagConfigValidator (save-gate), exactly as the sibling editors do — no inline validation here. *@
 @using ZB.MOM.WW.OtOpcUa.AdminUI.Uns.TagEditors
+@using ZB.MOM.WW.OtOpcUa.Core.Abstractions
+@using ZB.MOM.WW.OtOpcUa.Driver.Sql.Contracts
+@using ZB.MOM.WW.OtOpcUa.AdminUI.Components.Shared.Drivers
+@using ZB.MOM.WW.OtOpcUa.AdminUI.Components.Shared.Drivers.Pickers
 
-<div class="text-muted small">Sql tag editor — coming soon (Task 20).</div>
+<div class="row g-2">
+    <div class="col-md-4"><label class="form-label">Model</label>
+        <select class="form-select form-select-sm" value="@_m.Model" @onchange="@(e => Update(() => _m.Model = ParseEnum(e.Value, SqlTagModel.KeyValue)))">
+            @* Query is deferred (P3) and rejected by the parser/validator — only offer the two v1 models. *@
+            <option value="@SqlTagModel.KeyValue">KeyValue</option>
+            <option value="@SqlTagModel.WideRow">WideRow</option>
+        </select></div>
+    <div class="col-md-5"><label class="form-label">Table or view</label>
+        <input class="form-control form-control-sm mono" value="@_m.Table" placeholder="dbo.TagValues" @onchange="@(e => Update(() => _m.Table = NullIfBlank(e.Value)))" /></div>
+    <div class="col-md-3"><label class="form-label">Type override</label>
+        <select class="form-select form-select-sm" value="@(_m.Type?.ToString() ?? "")" @onchange="@(e => Update(() => _m.Type = ParseNullableEnum<DriverDataType>(e.Value)))">
+            <option value="">(infer from column)</option>
+            @foreach (var v in Enum.GetValues<DriverDataType>()) { <option value="@v">@v</option> }
+        </select></div>
+</div>
+
+@if (_m.Model == SqlTagModel.KeyValue)
+{
+    <div class="row g-2 mt-1">
+        <div class="col-md-4"><label class="form-label">Key column</label>
+            <input class="form-control form-control-sm mono" value="@_m.KeyColumn" placeholder="tag_name" @onchange="@(e => Update(() => _m.KeyColumn = NullIfBlank(e.Value)))" /></div>
+        <div class="col-md-4"><label class="form-label">Key value</label>
+            <input class="form-control form-control-sm mono" value="@_m.KeyValue" placeholder="Line1.Speed" @onchange="@(e => Update(() => _m.KeyValue = e.Value?.ToString()))" />
+            <div class="form-text">Bound as a parameter — never interpolated.</div></div>
+        <div class="col-md-4"><label class="form-label">Value column</label>
+            <input class="form-control form-control-sm mono" value="@_m.ValueColumn" placeholder="num_value" @onchange="@(e => Update(() => _m.ValueColumn = NullIfBlank(e.Value)))" /></div>
+    </div>
+}
+else
+{
+    <div class="row g-2 mt-1">
+        <div class="col-md-4"><label class="form-label">Value column</label>
+            <input class="form-control form-control-sm mono" value="@_m.ColumnName" placeholder="oven_temp" @onchange="@(e => Update(() => _m.ColumnName = NullIfBlank(e.Value)))" />
+            <div class="form-text">The column this tag reads from the selected row.</div></div>
+        <div class="col-md-4"><label class="form-label">Row selector</label>
+            <select class="form-select form-select-sm" value="@_selectorMode" @onchange="@(e => OnSelectorModeChanged(e.Value?.ToString()))">
+                <option value="Where">Where column = value</option>
+                <option value="Newest">Newest by timestamp</option>
+            </select></div>
+        @if (_selectorMode == "Where")
+        {
+            <div class="col-md-2"><label class="form-label">Where column</label>
+                <input class="form-control form-control-sm mono" value="@_m.RowSelector.WhereColumn" placeholder="station_id" @onchange="@(e => Update(() => _m.RowSelector.WhereColumn = NullIfBlank(e.Value)))" /></div>
+            <div class="col-md-2"><label class="form-label">Where value</label>
+                <input class="form-control form-control-sm mono" value="@_m.RowSelector.WhereValue" placeholder="7" @onchange="@(e => Update(() => _m.RowSelector.WhereValue = e.Value?.ToString()))" /></div>
+        }
+        else
+        {
+            <div class="col-md-4"><label class="form-label">Order-by (timestamp) column</label>
+                <input class="form-control form-control-sm mono" value="@_m.RowSelector.TopByTimestamp" placeholder="sample_ts" @onchange="@(e => Update(() => _m.RowSelector.TopByTimestamp = NullIfBlank(e.Value)))" /></div>
+        }
+    </div>
+}
+
+<div class="row g-2 mt-1">
+    <div class="col-md-6"><label class="form-label">Timestamp column <span class="text-muted small">(optional)</span></label>
+        <input class="form-control form-control-sm mono" value="@_m.TimestampColumn" placeholder="sample_ts" @onchange="@(e => Update(() => _m.TimestampColumn = NullIfBlank(e.Value)))" />
+        <div class="form-text">Source-timestamp column; blank ⇒ the driver stamps the poll time.</div></div>
+    <div class="col-12 mt-1">
+        <button type="button" class="btn btn-sm btn-outline-secondary" @onclick="@(() => _showPicker = true)">Build address</button>
+    </div>
+</div>
+
+@if (_showPicker)
+{
+    <DriverTagPicker @bind-Visible="_showPicker"
+                     Title="Sql tag builder"
+                     CurrentAddress="@_pickerAddress"
+                     OnPickAddress="@OnAddressPicked">
+        <SqlAddressPickerBody CurrentAddress="@_pickerAddress"
+                              CurrentAddressChanged="@((s) => _pickerAddress = s)"
+                              GetConfigJson="@GetDriverConfigJson" />
+    </DriverTagPicker>
+}
 
 @code {
     /// <summary>The tag's current TagConfig JSON.</summary>
@@ -23,13 +101,111 @@
 
     private SqlTagConfigModel _m = new();
     private string? _lastConfigJson;
+    private bool _showPicker;
+    private string _pickerAddress = "";
 
-    // Re-parse only when the incoming JSON actually changes, so an unrelated parent re-render can't reset
-    // an in-progress edit (mirrors the other typed editors).
+    // Local UI discriminator for the WideRow row selector (where-pair vs newest-by-timestamp). The model
+    // carries no explicit selector "mode" — it is inferred from which selector fields are populated. Kept in
+    // the editor (not the model) because an operator mid-edit may have BOTH selector fields blank, a state
+    // the mode can't be re-derived from; DeriveSelectorMode only overrides it when the model unambiguously
+    // says otherwise, so switching to "Newest" then round-tripping doesn't snap back to "Where".
+    private string _selectorMode = "Where";
+
+    // Re-parse only when the incoming JSON actually changes, so an unrelated parent re-render (Blazor Server
+    // live-status pushes do this) can't reset the user's in-progress edits (mirrors the other typed editors).
     protected override void OnParametersSet()
     {
         if (ConfigJson == _lastConfigJson) { return; }
         _lastConfigJson = ConfigJson;
         _m = SqlTagConfigModel.FromJson(ConfigJson);
+        DeriveSelectorMode();
+    }
+
+    // Sets the row-selector mode from the model ONLY when the populated fields make it unambiguous; leaves
+    // the operator's current choice untouched when both selector fields are blank (an in-progress edit).
+    private void DeriveSelectorMode()
+    {
+        if (!string.IsNullOrWhiteSpace(_m.RowSelector.TopByTimestamp) && string.IsNullOrWhiteSpace(_m.RowSelector.WhereColumn))
+        {
+            _selectorMode = "Newest";
+        }
+        else if (!string.IsNullOrWhiteSpace(_m.RowSelector.WhereColumn))
+        {
+            _selectorMode = "Where";
+        }
+    }
+
+    // TryParse so a bad/empty change value can never throw into the Blazor circuit — it falls back. Reads by
+    // NAME (never an ordinal cast), matching the model's strict name-string serialisation.
+    private static TEnum ParseEnum<TEnum>(object? v, TEnum fallback) where TEnum : struct, Enum
+        => Enum.TryParse<TEnum>(v?.ToString(), out var r) ? r : fallback;
+
+    // "" (the "(infer)" option) ⇒ null; a parseable NAME ⇒ that type; anything else ⇒ null. Enum round-trip
+    // is by name — never an ordinal cast — so the model re-serialises `type` as its strict name string.
+    private static TEnum? ParseNullableEnum<TEnum>(object? v) where TEnum : struct, Enum
+    {
+        var s = v?.ToString();
+        if (string.IsNullOrEmpty(s)) { return null; }
+        return Enum.TryParse<TEnum>(s, out var r) ? r : null;
+    }
+
+    // Identifier fields (table/column names): a blank input means "absent" — store null so ToJson omits the
+    // key. (KeyValue/WhereValue are deliberately NOT run through this: the model treats an empty-string value
+    // as present-and-empty, distinct from absent, so those keep e.Value verbatim.)
+    private static string? NullIfBlank(object? v)
+    {
+        var s = v?.ToString();
+        return string.IsNullOrWhiteSpace(s) ? null : s;
+    }
+
+    private async Task Update(Action apply)
+    {
+        apply();
+        await ConfigJsonChanged.InvokeAsync(_m.ToJson());
+    }
+
+    // The WideRow selector is either a where-pair OR newest-by-timestamp — never both. Clear the fields of
+    // the mode being left so the composed blob carries exactly one selector (a stale where-pair would win
+    // over topByTimestamp at read time, silently overriding the operator's choice).
+    private async Task OnSelectorModeChanged(string? mode)
+    {
+        _selectorMode = mode == "Newest" ? "Newest" : "Where";
+        await Update(() =>
+        {
+            if (_selectorMode == "Newest")
+            {
+                _m.RowSelector.WhereColumn = null;
+                _m.RowSelector.WhereValue = null;
+            }
+            else
+            {
+                _m.RowSelector.TopByTimestamp = null;
+            }
+        });
+    }
+
+    // The Sql picker emits a COMPLETE parser-shaped TagConfig blob (not a single address token like the
+    // other drivers' pickers). Parse it through the model and adopt its mapping fields onto the working
+    // model — mutating _m in place preserves any platform keys already on the tag (e.g. isHistorized) that
+    // the picker never authors.
+    private async Task OnAddressPicked(string blob)
+    {
+        if (string.IsNullOrWhiteSpace(blob)) { return; }
+        var picked = SqlTagConfigModel.FromJson(blob);
+        await Update(() =>
+        {
+            _m.Model = picked.Model;
+            _m.Table = picked.Table;
+            _m.KeyColumn = picked.KeyColumn;
+            _m.KeyValue = picked.KeyValue;
+            _m.ValueColumn = picked.ValueColumn;
+            _m.ColumnName = picked.ColumnName;
+            _m.TimestampColumn = picked.TimestampColumn;
+            _m.Type = picked.Type;
+            _m.RowSelector.WhereColumn = picked.RowSelector.WhereColumn;
+            _m.RowSelector.WhereValue = picked.RowSelector.WhereValue;
+            _m.RowSelector.TopByTimestamp = picked.RowSelector.TopByTimestamp;
+        });
+        DeriveSelectorMode();
     }
 }

src/Server/ZB.MOM.WW.OtOpcUa.Host/Drivers/DriverFactoryBootstrap.cs

@@ -18,6 +18,7 @@ using FocasProbe     = Driver.FOCAS.FocasDriverProbe;
 using OpcUaProbe     = Driver.OpcUaClient.OpcUaClientDriverProbe;
 using GalaxyProbe    = Driver.Galaxy.GalaxyDriverProbe;
 using CalculationProbe = Driver.Calculation.CalculationDriverProbe;
+using SqlProbe       = Driver.Sql.SqlDriverProbe;
 
 /// <summary>
 ///     Wires every cross-platform driver assembly's <c>Register(registry, loggerFactory)</c>
@@ -122,6 +123,7 @@ public static class DriverFactoryBootstrap
         services.TryAddEnumerable(ServiceDescriptor.Singleton<IDriverProbe, OpcUaProbe>());
         services.TryAddEnumerable(ServiceDescriptor.Singleton<IDriverProbe, GalaxyProbe>());
         services.TryAddEnumerable(ServiceDescriptor.Singleton<IDriverProbe, CalculationProbe>());
+        services.TryAddEnumerable(ServiceDescriptor.Singleton<IDriverProbe, SqlProbe>());
 
         return services;
     }
@@ -146,6 +148,7 @@ public static class DriverFactoryBootstrap
         Driver.Modbus.ModbusDriverFactoryExtensions.Register(registry, loggerFactory);
         Driver.OpcUaClient.OpcUaClientDriverFactoryExtensions.Register(registry, loggerFactory, secretResolver);
         Driver.S7.S7DriverFactoryExtensions.Register(registry);
+        Driver.Sql.SqlDriverFactoryExtensions.Register(registry, loggerFactory);
         Driver.TwinCAT.TwinCATDriverFactoryExtensions.Register(registry);
     }
 }

src/Server/ZB.MOM.WW.OtOpcUa.Host/ZB.MOM.WW.OtOpcUa.Host.csproj

@@ -76,6 +76,7 @@
         <ProjectReference Include="..\..\Drivers\ZB.MOM.WW.OtOpcUa.Driver.Modbus\ZB.MOM.WW.OtOpcUa.Driver.Modbus.csproj"/>
         <ProjectReference Include="..\..\Drivers\ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient\ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.csproj"/>
         <ProjectReference Include="..\..\Drivers\ZB.MOM.WW.OtOpcUa.Driver.S7\ZB.MOM.WW.OtOpcUa.Driver.S7.csproj"/>
+        <ProjectReference Include="..\..\Drivers\ZB.MOM.WW.OtOpcUa.Driver.Sql\ZB.MOM.WW.OtOpcUa.Driver.Sql.csproj"/>
         <ProjectReference Include="..\..\Drivers\ZB.MOM.WW.OtOpcUa.Driver.TwinCAT\ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.csproj"/>
     </ItemGroup>
 

src/Server/ZB.MOM.WW.OtOpcUa.Runtime/ScriptedAlarms/ScriptedAlarmHostActor.cs

@@ -288,8 +288,101 @@ public sealed class ScriptedAlarmHostActor : ReceiveActor
         // so a re-Apply with a fresh union simply supersedes the old one — no explicit unregister needed.
         _mux?.Tell(new DependencyMuxActor.RegisterInterest(msg.DepRefs, Self));
         _log.Debug("ScriptedAlarmHost: loaded; registered mux interest for {Count} dep refs", msg.DepRefs.Count);
+
+        ReassertConditionNodes();
     }
 
+    /// <summary>
+    ///     #487 — re-project every loaded alarm that is NOT in the Part 9 "no-event" position back onto
+    ///     its condition node, right after a (re)load.
+    ///
+    ///     <para>
+    ///         <b>The bug this closes.</b> A deploy that triggers a FULL address-space rebuild clears
+    ///         <c>_alarmConditions</c> and re-materialises every condition node fresh — inactive, acked,
+    ///         confirmed, unshelved. The engine, meanwhile, restores each alarm's persisted state and
+    ///         re-derives Active from the predicate, so a still-active alarm ends the reload
+    ///         <i>correctly Active in the engine</i> but produces <see cref="EmissionKind.None"/> (there
+    ///         is no transition to report) — and <see cref="OnEngineEmission"/> drops None. Nothing then
+    ///         writes the node, so an active alarm with static dependencies reads NORMAL to every OPC UA
+    ///         client until its next real transition, which may never come. Same shape as the VirtualTag
+    ///         redeploy-reset the <c>ReassertValue</c> fix closed.
+    ///     </para>
+    ///
+    ///     <para>
+    ///         <b>Node-only, by construction.</b> This sends <see cref="OpcUaPublishActor.AlarmStateUpdate"/>
+    ///         and nothing else — it never publishes to the <c>alerts</c> topic and never touches the
+    ///         telemetry hub. That is the whole reason it reads <see cref="ScriptedAlarmEngine.GetProjections"/>
+    ///         (a plain read returning <see cref="ScriptedAlarmProjection"/>) rather than re-emitting: an
+    ///         <c>alerts</c> row per alarm per deploy would append a duplicate historian / AVEVA record
+    ///         every time anyone deploys — the alarm analogue of the VirtualTag M1 historian issue.
+    ///     </para>
+    ///
+    ///     <para>
+    ///         <b>Ordering.</b> <c>DriverHostActor</c> Tells <c>RebuildAddressSpace</c> to the publish
+    ///         actor BEFORE it Tells <see cref="ApplyScriptedAlarms"/> here, and this runs later still —
+    ///         after an <c>await</c>ed <see cref="ScriptedAlarmEngine.LoadAsync"/> pipes back. Both Tells
+    ///         enqueue synchronously into the publish actor's local mailbox, so the re-materialise is
+    ///         already queued ahead of these writes: the node exists by the time they are handled.
+    ///     </para>
+    ///
+    ///     <para>
+    ///         <b>Why only non-normal alarms.</b> An alarm sitting in the no-event position already
+    ///         matches what the materialise just built, so writing it would be a pure no-op on state —
+    ///         but it would still overwrite the node's Message (the materialise seeds it with the alarm's
+    ///         display name; a projection carries the resolved template). Skipping them keeps a
+    ///         never-fired alarm byte-identical to a deploy without this pass, and keeps the write count
+    ///         at zero on the overwhelmingly common all-normal deploy.
+    ///     </para>
+    ///
+    ///     <para>
+    ///         <b>Duplicate events.</b> None. <c>WriteAlarmCondition</c>'s delta-gate compares the
+    ///         incoming snapshot against the node's CURRENT state, so a re-assert onto a freshly
+    ///         materialised (normal) node is a genuine delta and fires one Part 9 event — correct, since
+    ///         the rebuild reset what clients see — while a re-assert onto a surgically-preserved node
+    ///         that already holds the same state is suppressed. This write is ungated by redundancy role,
+    ///         like every other node write here: the Secondary keeps its address space warm for failover.
+    ///     </para>
+    /// </summary>
+    private void ReassertConditionNodes()
+    {
+        var reasserted = 0;
+        foreach (var projection in _engine.GetProjections())
+        {
+            if (IsInNoEventPosition(projection.Condition))
+            {
+                continue;
+            }
+
+            _publishActor.Tell(new OpcUaPublishActor.AlarmStateUpdate(
+                AlarmNodeId: projection.AlarmId,
+                State: ToSnapshot(projection),
+                // The instant the state we are re-asserting actually came about — NOT the deploy time.
+                // A client reading Time/ReceiveTime after a rebuild should still see when the alarm went
+                // active, not when the address space happened to be rebuilt.
+                TimestampUtc: projection.Condition.LastTransitionUtc,
+                Realm: AddressSpaceRealm.Uns));
+            reasserted++;
+        }
+
+        if (reasserted > 0)
+        {
+            _log.Info("ScriptedAlarmHost: re-asserted {Count} non-normal condition node(s) after (re)load", reasserted);
+        }
+    }
+
+    /// <summary>Whether <paramref name="condition"/> sits in the Part 9 "no-event" position — exactly the
+    /// state <see cref="AlarmConditionState.Fresh"/> produces and a freshly materialised condition node
+    /// already carries. Anything else (active, unacknowledged, unconfirmed, disabled, or shelved) is state
+    /// a rebuild would silently lose, so it is what <see cref="ReassertConditionNodes"/> re-projects.</summary>
+    /// <param name="condition">The engine's current condition state.</param>
+    /// <returns><c>true</c> when the condition carries nothing a rebuild could lose.</returns>
+    private static bool IsInNoEventPosition(AlarmConditionState condition)
+        => condition.Enabled == AlarmEnabledState.Enabled
+           && condition.Active == AlarmActiveState.Inactive
+           && condition.Acked == AlarmAckedState.Acknowledged
+           && condition.Confirmed == AlarmConfirmedState.Confirmed
+           && condition.Shelving.Kind == ShelvingKind.Unshelved;
+
     private void OnDependencyChanged(VirtualTagActor.DependencyValueChanged msg)
     {
         // Feed the live value into the upstream the engine subscribes from. #478 — carry the source
@@ -594,18 +687,38 @@ public sealed class ScriptedAlarmHostActor : ReceiveActor
     /// Severity is the OPC UA 1..1000 value <see cref="SeverityToInt"/> derives from the coarse engine
     /// bucket, cast to the <c>ushort</c> the SDK <c>SetSeverity</c> expects. Shelving's 3-way Core kind
     /// maps 1:1 onto the Commons <see cref="AlarmShelvingKind"/>.</summary>
-    private static AlarmConditionSnapshot ToSnapshot(ScriptedAlarmEvent e) => new(
-        Active: e.Condition.Active == AlarmActiveState.Active,
-        Acknowledged: e.Condition.Acked == AlarmAckedState.Acknowledged,
-        Confirmed: e.Condition.Confirmed == AlarmConfirmedState.Confirmed,
-        Enabled: e.Condition.Enabled == AlarmEnabledState.Enabled,
-        Shelving: MapShelving(e.Condition.Shelving.Kind),
-        Severity: (ushort)SeverityToInt(e.Severity),
-        Message: e.Message,
+    private static AlarmConditionSnapshot ToSnapshot(ScriptedAlarmEvent e)
+        => ToSnapshot(e.Condition, e.Severity, e.Message, e.WorstInputStatusCode);
+
+    /// <summary>#487 — the same projection for a <see cref="ScriptedAlarmProjection"/>: a state READ used
+    /// to restore a condition node after a rebuild, never an emission. Shares
+    /// <see cref="ToSnapshot(AlarmConditionState, AlarmSeverity, string, uint)"/> with the transition path
+    /// so a re-asserted node is byte-identical to what the alarm's own transition would have written.</summary>
+    /// <param name="p">The engine projection to map.</param>
+    /// <returns>The Commons snapshot the SDK sink projects onto the condition node.</returns>
+    private static AlarmConditionSnapshot ToSnapshot(ScriptedAlarmProjection p)
+        => ToSnapshot(p.Condition, p.Severity, p.Message, p.WorstInputStatusCode);
+
+    /// <summary>The single Core → Commons condition projection, shared by the emission and re-assert
+    /// paths.</summary>
+    /// <param name="condition">The Part 9 condition state.</param>
+    /// <param name="severity">The engine's coarse severity bucket.</param>
+    /// <param name="message">The resolved condition message.</param>
+    /// <param name="worstInputStatusCode">The worst OPC UA StatusCode across the script's input tags.</param>
+    /// <returns>The Commons snapshot the SDK sink projects onto the condition node.</returns>
+    private static AlarmConditionSnapshot ToSnapshot(
+        AlarmConditionState condition, AlarmSeverity severity, string message, uint worstInputStatusCode) => new(
+        Active: condition.Active == AlarmActiveState.Active,
+        Acknowledged: condition.Acked == AlarmAckedState.Acknowledged,
+        Confirmed: condition.Confirmed == AlarmConfirmedState.Confirmed,
+        Enabled: condition.Enabled == AlarmEnabledState.Enabled,
+        Shelving: MapShelving(condition.Shelving.Kind),
+        Severity: (ushort)SeverityToInt(severity),
+        Message: message,
         // #478 — the condition's Quality is the worst quality across the script's input tags at evaluation
         // time (carried on the event by the engine). A transition fired while an input is Uncertain projects
         // Uncertain here so the full-snapshot write doesn't clobber quality back to Good.
-        Quality: QualityFromStatus(e.WorstInputStatusCode));
+        Quality: QualityFromStatus(worstInputStatusCode));
 
     /// <summary>Maps the Core <see cref="ShelvingKind"/> onto the Commons <see cref="AlarmShelvingKind"/>
     /// mirror (the Commons assembly can't see the Core enum).</summary>

tests/Core/ZB.MOM.WW.OtOpcUa.Configuration.Tests/DraftValidatorSqlSecretTests.cs

@@ -0,0 +1,173 @@
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Configuration.Entities;
+using ZB.MOM.WW.OtOpcUa.Configuration.Validation;
+
+namespace ZB.MOM.WW.OtOpcUa.Configuration.Tests;
+
+/// <summary>
+///     The Gitea #498 deploy gate: a <c>Sql</c> driver's persisted config may never carry a literal
+///     <c>connectionString</c>. The typed DTO already drops the key on <em>read</em>; these pin the
+///     <em>write</em> side, which is where a credential would actually land in the config database.
+/// </summary>
+[Trait("Category", "Unit")]
+public sealed class DraftValidatorSqlSecretTests
+{
+    private const string Code = "SqlConnectionStringPersisted";
+
+    /// <summary>A realistic leak: the literal an operator would paste into a raw-JSON config textarea.</summary>
+    private const string LeakedConfig =
+        """{"provider":"SqlServer","connectionString":"Server=sql,1433;Database=Mes;User ID=sa;Password=hunter2"}""";
+
+    private static DriverInstance SqlDriver(string config) => new()
+    {
+        DriverInstanceId = "di-sql", ClusterId = "c", Name = "line3-sql",
+        DriverType = "Sql", DriverConfig = config,
+    };
+
+    private static Device Device(string driverInstanceId, string config) => new()
+    {
+        DeviceId = "dev-1", DriverInstanceId = driverInstanceId, Name = "Device1", DeviceConfig = config,
+    };
+
+    private static DraftSnapshot Draft(DriverInstance driver, Device? device = null) => new()
+    {
+        GenerationId = 1,
+        ClusterId = "c",
+        DriverInstances = [driver],
+        Devices = device is null ? [] : [device],
+    };
+
+    [Fact]
+    public void Literal_connectionString_in_DriverConfig_is_a_deploy_error()
+    {
+        var errors = DraftValidator.Validate(Draft(SqlDriver(LeakedConfig)));
+
+        errors.ShouldContain(e => e.Code == Code && e.Context == "di-sql");
+    }
+
+    /// <summary>
+    ///     The error text reaches the AdminUI, the deploy log and the audit trail, so it must describe the
+    ///     problem without repeating the credential it is refusing to store.
+    /// </summary>
+    [Fact]
+    public void Error_message_does_not_echo_the_credential()
+    {
+        var error = DraftValidator.Validate(Draft(SqlDriver(LeakedConfig))).First(e => e.Code == Code);
+
+        error.Message.ShouldNotContain("hunter2");
+        error.Message.ShouldNotContain("Server=sql,1433");
+        error.Message.ShouldContain("connectionStringRef");
+    }
+
+    /// <summary>
+    ///     System.Text.Json binds <c>ConnectionString</c> to a <c>connectionString</c> property by default, so
+    ///     a case variant is the same key — matching it ordinally would leave the obvious bypass wide open.
+    /// </summary>
+    [Theory]
+    [InlineData("ConnectionString")]
+    [InlineData("CONNECTIONSTRING")]
+    [InlineData("connectionstring")]
+    public void Key_match_is_case_insensitive(string key)
+    {
+        var config = $$"""{"provider":"SqlServer","{{key}}":"Server=s;Password=p"}""";
+
+        DraftValidator.Validate(Draft(SqlDriver(config)))
+            .ShouldContain(e => e.Code == Code && e.Context == "di-sql");
+    }
+
+    /// <summary>
+    ///     DeviceConfig is merged onto DriverConfig before the driver's DTO sees it, so a credential pasted
+    ///     there is the identical leak and must fail the same way.
+    /// </summary>
+    [Fact]
+    public void Literal_connectionString_in_a_Sql_devices_DeviceConfig_is_a_deploy_error()
+    {
+        var draft = Draft(SqlDriver("""{"connectionStringRef":"DevSql"}"""), Device("di-sql", LeakedConfig));
+
+        DraftValidator.Validate(draft).ShouldContain(e => e.Code == Code && e.Context == "dev-1");
+    }
+
+    [Fact]
+    public void A_properly_authored_connectionStringRef_passes()
+    {
+        var draft = Draft(
+            SqlDriver("""{"provider":"SqlServer","connectionStringRef":"DevSql","nullIsBad":true}"""),
+            Device("di-sql", """{"pollIntervalMs":1000}"""));
+
+        DraftValidator.Validate(draft).ShouldNotContain(e => e.Code == Code);
+    }
+
+    /// <summary>
+    ///     The rule is scoped to the Sql driver type. A non-Sql driver is not in its remit — widening the gate
+    ///     to every driver is a separate decision, and silently failing an unrelated driver's deploy here would
+    ///     be a regression, not defence in depth.
+    /// </summary>
+    [Fact]
+    public void A_non_Sql_driver_carrying_the_key_is_not_flagged_by_this_rule()
+    {
+        var modbus = new DriverInstance
+        {
+            DriverInstanceId = "di-mb", ClusterId = "c", Name = "mb",
+            DriverType = "Modbus", DriverConfig = LeakedConfig,
+        };
+
+        DraftValidator.Validate(Draft(modbus)).ShouldNotContain(e => e.Code == Code);
+    }
+
+    /// <summary>
+    ///     A device under a <em>different</em> driver must not be attributed to the Sql instance — the device
+    ///     scan keys off DriverInstanceId, and getting that wrong would flag innocent devices.
+    /// </summary>
+    [Fact]
+    public void A_device_under_a_non_Sql_driver_is_not_flagged()
+    {
+        var draft = new DraftSnapshot
+        {
+            GenerationId = 1,
+            ClusterId = "c",
+            DriverInstances =
+            [
+                SqlDriver("""{"connectionStringRef":"DevSql"}"""),
+                new DriverInstance
+                {
+                    DriverInstanceId = "di-mb", ClusterId = "c", Name = "mb",
+                    DriverType = "Modbus", DriverConfig = "{}",
+                },
+            ],
+            Devices = [Device("di-mb", LeakedConfig)],
+        };
+
+        DraftValidator.Validate(draft).ShouldNotContain(e => e.Code == Code);
+    }
+
+    /// <summary>
+    ///     Malformed or non-object config must not throw out of the validator: shaping the JSON is another
+    ///     rule's job, and a parse failure here would take down every other check in the same pass.
+    /// </summary>
+    [Theory]
+    [InlineData("")]
+    [InlineData("   ")]
+    [InlineData("not json at all")]
+    [InlineData("[1,2,3]")]
+    [InlineData("\"connectionString\"")]
+    [InlineData("{\"provider\":\"SqlServer\"")]
+    public void Malformed_config_neither_throws_nor_flags(string config)
+    {
+        Should.NotThrow(() => DraftValidator.Validate(Draft(SqlDriver(config))))
+            .ShouldNotContain(e => e.Code == Code);
+    }
+
+    /// <summary>
+    ///     Only the top level is scanned. The DTO is flat, so a nested occurrence cannot bind to anything and
+    ///     is not the credential-shaped mistake this rule exists to catch; flagging it would be a false
+    ///     positive on, say, a tag blob that happens to describe a connection string.
+    /// </summary>
+    [Fact]
+    public void A_nested_connectionString_is_not_flagged()
+    {
+        var config = """{"connectionStringRef":"DevSql","notes":{"connectionString":"documented elsewhere"}}""";
+
+        DraftValidator.Validate(Draft(SqlDriver(config))).ShouldNotContain(e => e.Code == Code);
+    }
+}

tests/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions.Tests/StatusCodeParityTests.cs

@@ -0,0 +1,160 @@
+using System.Reflection;
+using Shouldly;
+using Xunit;
+
+namespace ZB.MOM.WW.OtOpcUa.Core.Abstractions.Tests;
+
+/// <summary>
+///     Guards every driver's hard-coded OPC UA status-code constant against
+///     <see cref="Opc.Ua.StatusCodes"/> — the pinned SDK is the oracle, and a constant whose
+///     <em>name</em> disagrees with its <em>value</em> fails here.
+///     <para><b>Why the drivers hard-code these at all.</b> The driver layer is deliberately SDK-free: a
+///     driver assembly must not drag in the OPC UA stack just to spell a status code, so each one declares
+///     the handful it needs as bare <c>uint</c> literals. That is a sound layering decision with one
+///     failure mode — nothing checks the literal against the name — and it is exactly the failure mode
+///     Gitea #497 found in six places across four drivers.</para>
+///     <para><b>Discovery is reflection-driven, not a hand-copied list</b> (the same convention
+///     <see cref="DriverTypeNamesGuardTests"/> uses): the test scans every
+///     <c>ZB.MOM.WW.OtOpcUa.Driver.*.dll</c> deployed to its output directory for <c>const uint</c> fields
+///     whose name reads as a status code, so a brand-new driver assembly referenced by this project is
+///     covered automatically, with no edit here.</para>
+///     <para><b>An inline literal is invisible to this guard.</b> Reflection can only see a <em>named</em>
+///     constant, so <c>StatusCode: 0x800B0000u, // BadTimeout</c> written at a call site is unguarded —
+///     which is how <c>GalaxyDriver</c> shipped <c>BadServiceUnsupported</c> under a <c>BadTimeout</c>
+///     comment. Hoist a status literal into a named constant rather than writing it at the call site.</para>
+/// </summary>
+public sealed class StatusCodeParityTests
+{
+    /// <summary>
+    ///     Name prefixes that mark a <c>uint</c> constant as an OPC UA status code. These are the three
+    ///     Part 4 severity categories, so they cover the whole space by construction — a status constant
+    ///     that does not start with one of them is not a status constant.
+    /// </summary>
+    private static readonly string[] StatusPrefixes = ["Good", "Uncertain", "Bad"];
+
+    /// <summary>
+    ///     Field-name prefixes stripped before the name is looked up on <see cref="Opc.Ua.StatusCodes"/>.
+    ///     Drivers vary the spelling (<c>SampleMapper.StatusBadNoData</c> vs
+    ///     <c>SqlStatusCodes.BadTimeout</c>); the SDK member is <c>BadNoData</c> either way.
+    /// </summary>
+    private static readonly string[] NamePrefixesToStrip = ["Status"];
+
+    /// <summary>Every <c>Opc.Ua.StatusCodes</c> member, by name — the oracle this test checks against.</summary>
+    private static readonly IReadOnlyDictionary<string, uint> SdkStatusCodes =
+        typeof(Opc.Ua.StatusCodes)
+            .GetFields(BindingFlags.Public | BindingFlags.Static)
+            .Where(f => f.IsLiteral && f.FieldType == typeof(uint))
+            .ToDictionary(f => f.Name, f => (uint)f.GetRawConstantValue()!, StringComparer.Ordinal);
+
+    /// <summary>
+    ///     Every status-shaped <c>const uint</c> declared anywhere in the deployed driver assemblies, as
+    ///     <c>(assembly, declaring type, field name, SDK member name, declared value)</c>.
+    /// </summary>
+    /// <remarks>
+    ///     Non-public types and fields are included on purpose — <c>SampleMapper.StatusBadNoData</c> is a
+    ///     <c>private const</c> on an <c>internal</c> class, and it carried one of the #497 defects. Access
+    ///     modifiers say nothing about whether a value reaches an OPC UA client.
+    /// </remarks>
+    public static TheoryData<string, string, string, string, uint> DeclaredStatusConstants()
+    {
+        var data = new TheoryData<string, string, string, string, uint>();
+
+        var binDir = Path.GetDirectoryName(typeof(StatusCodeParityTests).Assembly.Location)!;
+        foreach (var dll in Directory.GetFiles(binDir, "ZB.MOM.WW.OtOpcUa.Driver.*.dll").OrderBy(p => p, StringComparer.Ordinal))
+        {
+            Assembly asm;
+            try { asm = Assembly.LoadFrom(dll); }
+            catch { continue; }
+
+            Type?[] types;
+            try { types = asm.GetTypes(); }
+            catch (ReflectionTypeLoadException ex) { types = ex.Types; }
+
+            foreach (var type in types)
+            {
+                if (type is null) continue;
+
+                var fields = type.GetFields(
+                    BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static | BindingFlags.DeclaredOnly);
+
+                foreach (var field in fields)
+                {
+                    if (!field.IsLiteral || field.IsInitOnly || field.FieldType != typeof(uint)) continue;
+
+                    var sdkName = StripKnownPrefix(field.Name);
+                    if (!StatusPrefixes.Any(p => sdkName.StartsWith(p, StringComparison.Ordinal))) continue;
+
+                    data.Add(
+                        asm.GetName().Name!,
+                        type.FullName ?? type.Name,
+                        field.Name,
+                        sdkName,
+                        (uint)field.GetRawConstantValue()!);
+                }
+            }
+        }
+
+        return data;
+    }
+
+    /// <summary>Removes a leading <c>Status</c>-style prefix so the remainder can be looked up on the SDK type.</summary>
+    private static string StripKnownPrefix(string fieldName)
+    {
+        foreach (var prefix in NamePrefixesToStrip)
+        {
+            if (fieldName.Length > prefix.Length && fieldName.StartsWith(prefix, StringComparison.Ordinal))
+                return fieldName[prefix.Length..];
+        }
+
+        return fieldName;
+    }
+
+    /// <summary>
+    ///     A driver's status constant must carry the value the SDK gives the code it is named after.
+    /// </summary>
+    /// <param name="assembly">The declaring driver assembly (failure-message context).</param>
+    /// <param name="type">The declaring type's full name (failure-message context).</param>
+    /// <param name="field">The constant's name as declared.</param>
+    /// <param name="sdkName">The <see cref="Opc.Ua.StatusCodes"/> member the name resolves to.</param>
+    /// <param name="declared">The value the driver declares.</param>
+    [Theory]
+    [MemberData(nameof(DeclaredStatusConstants))]
+    public void Driver_status_constant_matches_the_pinned_SDK(
+        string assembly, string type, string field, string sdkName, uint declared)
+    {
+        SdkStatusCodes.ShouldContainKey(sdkName,
+            $"{type}.{field} (in {assembly}) reads as an OPC UA status code, but '{sdkName}' is not a member " +
+            "of Opc.Ua.StatusCodes. Either the constant is misnamed, or it is not a status code and should " +
+            "not start with Good/Uncertain/Bad.");
+
+        var expected = SdkStatusCodes[sdkName];
+        declared.ShouldBe(expected,
+            $"{type}.{field} (in {assembly}) is declared 0x{declared:X8}, but Opc.Ua.StatusCodes.{sdkName} " +
+            $"is 0x{expected:X8}" +
+            (SdkStatusCodes.FirstOrDefault(kv => kv.Value == declared) is { Key: { } actual } && actual.Length > 0
+                ? $" — 0x{declared:X8} is actually {actual}, which is what OPC UA clients would branch on."
+                : ". The declared value is not any OPC UA status code."));
+    }
+
+    /// <summary>
+    ///     Discovery must find constants in more than one driver assembly. A zero (or near-zero) here means
+    ///     the bin scan broke or the drivers stopped declaring these by convention — either way the theory
+    ///     above would pass vacuously, which is the one outcome a guard test must never do quietly.
+    /// </summary>
+    [Fact]
+    public void Discovery_finds_status_constants_across_multiple_driver_assemblies()
+    {
+        var found = DeclaredStatusConstants();
+        found.Count.ShouldBeGreaterThan(20,
+            "the driver bin scan found almost no status constants — the assemblies did not deploy to bin, " +
+            "or the naming convention changed");
+
+        var assemblies = found
+            .Select(row => row.Data.Item1)
+            .Distinct(StringComparer.Ordinal)
+            .ToArray();
+
+        assemblies.Length.ShouldBeGreaterThan(3,
+            "status constants were found in fewer than four driver assemblies: " + string.Join(", ", assemblies));
+    }
+}

tests/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions.Tests/ZB.MOM.WW.OtOpcUa.Core.Abstractions.Tests.csproj

@@ -12,6 +12,8 @@
     <ItemGroup>
         <PackageReference Include="xunit.v3"/>
         <PackageReference Include="Shouldly"/>
+        <!-- StatusCodeParityTests only; supplies Opc.Ua.StatusCodes as the oracle. -->
+        <PackageReference Include="OPCFoundation.NetStandard.Opc.Ua.Core"/>
         <PackageReference Include="Microsoft.NET.Test.Sdk"/>
         <PackageReference Include="xunit.runner.visualstudio">
             <PrivateAssets>all</PrivateAssets>
@@ -34,6 +36,11 @@
         <ProjectReference Include="..\..\..\src\Drivers\ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient\ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.csproj"/>
         <ProjectReference Include="..\..\..\src\Drivers\ZB.MOM.WW.OtOpcUa.Driver.Galaxy\ZB.MOM.WW.OtOpcUa.Driver.Galaxy.csproj"/>
         <ProjectReference Include="..\..\..\src\Drivers\ZB.MOM.WW.OtOpcUa.Driver.Calculation\ZB.MOM.WW.OtOpcUa.Driver.Calculation.csproj"/>
+        <ProjectReference Include="..\..\..\src\Drivers\ZB.MOM.WW.OtOpcUa.Driver.Sql\ZB.MOM.WW.OtOpcUa.Driver.Sql.csproj"/>
+        <!-- Ships no driver factory (it is a historian backend, not an Equipment driver), so the
+             DriverTypeNames guard skips it — but it does hard-code OPC UA status constants, which
+             puts it in StatusCodeParityTests' scope. -->
+        <ProjectReference Include="..\..\..\src\Drivers\ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway\ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.csproj"/>
     </ItemGroup>
 
 </Project>

tests/Core/ZB.MOM.WW.OtOpcUa.Core.ScriptedAlarms.Tests/ScriptedAlarmProjectionTests.cs

@@ -0,0 +1,180 @@
+using Serilog;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+using ZB.MOM.WW.OtOpcUa.Core.ScriptedAlarms;
+using ZB.MOM.WW.OtOpcUa.Core.Scripting;
+
+namespace ZB.MOM.WW.OtOpcUa.Core.ScriptedAlarms.Tests;
+
+/// <summary>
+///     #487 — <see cref="ScriptedAlarmEngine.GetProjections"/>: the read that lets a caller restore an
+///     alarm's condition node after a full address-space rebuild, without waiting for the alarm's next
+///     transition (which for a still-active alarm with static dependencies may never come).
+/// </summary>
+/// <remarks>
+///     The load that motivates this is deliberately the one that emits NOTHING: an alarm whose persisted
+///     state is already Active and whose predicate is still true produces <see cref="EmissionKind.None"/>,
+///     so the transition stream cannot carry its state. These tests pin both halves — the projection does
+///     report the state, and reading it does not fire an emission.
+/// </remarks>
+[Trait("Category", "Unit")]
+public sealed class ScriptedAlarmProjectionTests
+{
+    private static ScriptedAlarmDefinition Alarm(
+        string id = "HighTemp",
+        string predicate = """return (int)ctx.GetTag("Temp").Value > 100;""",
+        string msg = "Temp is {Temp}",
+        AlarmSeverity sev = AlarmSeverity.High) =>
+        new(AlarmId: id,
+            EquipmentPath: "Plant/Line1/Reactor",
+            AlarmName: id,
+            Kind: AlarmKind.AlarmCondition,
+            Severity: sev,
+            MessageTemplate: msg,
+            PredicateScriptSource: predicate);
+
+    /// <summary>An already-Active persisted state, as a store would hold it across a restart/redeploy.</summary>
+    private static AlarmConditionState PersistedActive(
+        string alarmId = "HighTemp",
+        AlarmAckedState acked = AlarmAckedState.Unacknowledged,
+        DateTime? lastTransitionUtc = null) =>
+        new(alarmId,
+            AlarmEnabledState.Enabled,
+            AlarmActiveState.Active,
+            acked,
+            AlarmConfirmedState.Confirmed,
+            ShelvingState.Unshelved,
+            lastTransitionUtc ?? DateTime.UtcNow,
+            LastActiveUtc: lastTransitionUtc ?? DateTime.UtcNow,
+            LastClearedUtc: null,
+            LastAckUtc: null, LastAckUser: null, LastAckComment: null,
+            LastConfirmUtc: null, LastConfirmUser: null, LastConfirmComment: null,
+            Comments: []);
+
+    private static ScriptedAlarmEngine Build(FakeUpstream up, IAlarmStateStore store)
+    {
+        var logger = new LoggerConfiguration().CreateLogger();
+        return new ScriptedAlarmEngine(up, store, new ScriptLoggerFactory(logger), logger);
+    }
+
+    /// <summary>The core of #487: a reload of a still-active alarm emits NOTHING, yet the projection
+    /// reports it Active — so a caller has a way to restore the node the rebuild reset.</summary>
+    [Fact]
+    public async Task A_still_active_alarm_emits_nothing_on_reload_but_projects_Active()
+    {
+        var up = new FakeUpstream();
+        up.Set("Temp", 150); // predicate still true — no transition to report
+        var store = new InMemoryAlarmStateStore();
+        await store.SaveAsync(PersistedActive(), TestContext.Current.CancellationToken);
+
+        using var eng = Build(up, store);
+        var emissions = new List<ScriptedAlarmEvent>();
+        eng.OnEvent += (_, e) => { lock (emissions) emissions.Add(e); }; // subscribe BEFORE the load
+
+        await eng.LoadAsync([Alarm()], TestContext.Current.CancellationToken);
+
+        // The premise. If this ever starts emitting, the bug's shape has changed and the re-assert
+        // in ScriptedAlarmHostActor may have become a duplicate rather than the only source of truth.
+        lock (emissions)
+        {
+            emissions.ShouldBeEmpty("a still-active alarm has no transition to report on reload");
+        }
+
+        var projection = eng.GetProjections().ShouldHaveSingleItem();
+        projection.AlarmId.ShouldBe("HighTemp");
+        projection.Condition.Active.ShouldBe(AlarmActiveState.Active);
+        projection.Condition.Acked.ShouldBe(AlarmAckedState.Unacknowledged);
+    }
+
+    /// <summary>The projection carries the definition's severity and the message template resolved against
+    /// the live value cache — so a re-asserted node is indistinguishable from one a real transition wrote.</summary>
+    [Fact]
+    public async Task Projection_carries_definition_severity_and_a_resolved_message()
+    {
+        var up = new FakeUpstream();
+        up.Set("Temp", 150);
+        var store = new InMemoryAlarmStateStore();
+        await store.SaveAsync(PersistedActive(), TestContext.Current.CancellationToken);
+
+        using var eng = Build(up, store);
+        await eng.LoadAsync([Alarm(sev: AlarmSeverity.Critical)], TestContext.Current.CancellationToken);
+
+        var projection = eng.GetProjections().ShouldHaveSingleItem();
+        projection.Severity.ShouldBe(AlarmSeverity.Critical);
+        projection.Message.ShouldBe("Temp is 150", "the template resolves against the current value cache");
+    }
+
+    /// <summary>Reading projections is a pure read — it must never raise <see cref="ScriptedAlarmEngine.OnEvent"/>,
+    /// or every deploy would append a duplicate historian / alerts row.</summary>
+    [Fact]
+    public async Task Reading_projections_never_fires_an_emission()
+    {
+        var up = new FakeUpstream();
+        up.Set("Temp", 150);
+        var store = new InMemoryAlarmStateStore();
+        await store.SaveAsync(PersistedActive(), TestContext.Current.CancellationToken);
+
+        using var eng = Build(up, store);
+        await eng.LoadAsync([Alarm()], TestContext.Current.CancellationToken);
+
+        var emissions = 0;
+        eng.OnEvent += (_, _) => Interlocked.Increment(ref emissions);
+
+        for (var i = 0; i < 5; i++) eng.GetProjections().ShouldNotBeEmpty();
+
+        Volatile.Read(ref emissions).ShouldBe(0);
+    }
+
+    /// <summary>An alarm that is genuinely normal projects the no-event position, so a caller can tell
+    /// "nothing to restore" from "restore this".</summary>
+    [Fact]
+    public async Task A_normal_alarm_projects_the_no_event_position()
+    {
+        var up = new FakeUpstream();
+        up.Set("Temp", 50); // predicate false
+        using var eng = Build(up, new InMemoryAlarmStateStore());
+
+        await eng.LoadAsync([Alarm()], TestContext.Current.CancellationToken);
+
+        var projection = eng.GetProjections().ShouldHaveSingleItem();
+        projection.Condition.Active.ShouldBe(AlarmActiveState.Inactive);
+        projection.Condition.Acked.ShouldBe(AlarmAckedState.Acknowledged);
+        projection.Condition.Enabled.ShouldBe(AlarmEnabledState.Enabled);
+        projection.Condition.Shelving.Kind.ShouldBe(ShelvingKind.Unshelved);
+    }
+
+    /// <summary>The worst-input quality rides the projection, so restoring a node whose script inputs are
+    /// Bad does not clobber its Quality back to Good (#478's invariant, on the re-assert path).</summary>
+    [Fact]
+    public async Task Projection_carries_the_last_observed_worst_input_quality()
+    {
+        var up = new FakeUpstream();
+        up.Set("Temp", 150);
+        var store = new InMemoryAlarmStateStore();
+        await store.SaveAsync(PersistedActive(), TestContext.Current.CancellationToken);
+
+        using var eng = Build(up, store);
+        await eng.LoadAsync([Alarm()], TestContext.Current.CancellationToken);
+        eng.GetProjections().ShouldHaveSingleItem().WorstInputStatusCode.ShouldBe(0u, "inputs start Good");
+
+        up.Push("Temp", 150, 0x80000000u); // input goes Bad — condition freezes, quality is annotated
+
+        // The push re-evaluates on a background worker; poll for the tracked bucket to move.
+        var deadline = DateTime.UtcNow.AddSeconds(10);
+        while (eng.GetProjections()[0].WorstInputStatusCode == 0u && DateTime.UtcNow < deadline)
+        {
+            await Task.Delay(20, TestContext.Current.CancellationToken);
+        }
+
+        (eng.GetProjections()[0].WorstInputStatusCode >> 30).ShouldBe(2u, "a Bad input projects Bad quality");
+    }
+
+    /// <summary>Before the first load there is nothing to project — the read is safe, not a throw.</summary>
+    [Fact]
+    public void Projections_are_empty_before_the_first_load()
+    {
+        using var eng = Build(new FakeUpstream(), new InMemoryAlarmStateStore());
+        eng.GetProjections().ShouldBeEmpty();
+    }
+}

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Runtime/StatusCodeMapTests.cs

@@ -19,12 +19,12 @@ public sealed class StatusCodeMapTests
     /// <param name="expected">The expected OPC UA status code.</param>
     [Theory]
     [InlineData((byte)192, 0x00000000u)]   // Good
-    [InlineData((byte)216, 0x00D80000u)]   // Good_LocalOverride
+    [InlineData((byte)216, 0x00960000u)]   // Good_LocalOverride
     [InlineData((byte)64,  0x40000000u)]   // Uncertain
-    [InlineData((byte)68,  0x40A40000u)]   // Uncertain_LastUsableValue
-    [InlineData((byte)80,  0x408D0000u)]   // Uncertain_SensorNotAccurate
-    [InlineData((byte)84,  0x408E0000u)]   // Uncertain_EngineeringUnitsExceeded
-    [InlineData((byte)88,  0x408F0000u)]   // Uncertain_SubNormal
+    [InlineData((byte)68,  0x40900000u)]   // Uncertain_LastUsableValue
+    [InlineData((byte)80,  0x40930000u)]   // Uncertain_SensorNotAccurate
+    [InlineData((byte)84,  0x40940000u)]   // Uncertain_EngineeringUnitsExceeded
+    [InlineData((byte)88,  0x40950000u)]   // Uncertain_SubNormal
     [InlineData((byte)0,   0x80000000u)]   // Bad
     [InlineData((byte)4,   0x80890000u)]   // Bad_ConfigurationError
     [InlineData((byte)8,   0x808A0000u)]   // Bad_NotConnected
@@ -132,9 +132,9 @@ public sealed class StatusCodeMapTests
     /// <param name="expected">The expected OPC DA category byte.</param>
     [Theory]
     [InlineData(0x00000000u, (byte)192)]  // Good
-    [InlineData(0x00D80000u, (byte)192)]  // GoodLocalOverride — still Good category
+    [InlineData(0x00960000u, (byte)192)]  // GoodLocalOverride — still Good category
     [InlineData(0x40000000u, (byte)64)]   // Uncertain
-    [InlineData(0x408F0000u, (byte)64)]   // UncertainSubNormal — still Uncertain category
+    [InlineData(0x40950000u, (byte)64)]   // UncertainSubNormal — still Uncertain category
     [InlineData(0x80000000u, (byte)0)]    // Bad
     [InlineData(0x808A0000u, (byte)0)]    // BadNotConnected — still Bad category
     [InlineData(0x80020000u, (byte)0)]    // BadInternalError — still Bad category

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.Tests/Mapping/GatewayQualityMapperTests.cs

@@ -7,7 +7,7 @@ public sealed class GatewayQualityMapperTests
 {
     [Theory]
     [InlineData(192, 0x00000000u)] // Good
-    [InlineData(216, 0x00D80000u)] // Good_LocalOverride
+    [InlineData(216, 0x00960000u)] // Good_LocalOverride
     [InlineData(64,  0x40000000u)] // Uncertain
     [InlineData(0,   0x80000000u)] // Bad
     [InlineData(8,   0x808A0000u)] // Bad_NotConnected

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.Tests/Mapping/SampleMapperTests.cs

@@ -37,7 +37,7 @@ public sealed class SampleMapperTests
     {
         var a = new HistorianAggregateSample { Tag = "T", /* Value unset, no Good quality */ EndTime = Ts(2026, 1, 1, 0, 0, 0) };
         var snap = SampleMapper.ToAggregateSnapshot(a);
-        Assert.Equal(0x800E0000u, snap.StatusCode); // BadNoData
+        Assert.Equal(0x809B0000u, snap.StatusCode); // BadNoData
         Assert.Null(snap.Value);
     }
 

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql.IntegrationTests/SqlServerReadTests.cs

@@ -475,6 +475,99 @@ public sealed class SqlServerReadTests
 
     // ---- helpers ----
 
+    // ---- design §8.1 catalog gate (Gitea #496), against a real INFORMATION_SCHEMA ----
+
+    /// <summary>
+    ///     The gate's live proof: an authored column that does not exist is refused by the allow-list at
+    ///     Initialize, so it never reaches a query — and its neighbour on the same table keeps reading.
+    /// </summary>
+    /// <remarks>
+    ///     Only a real SQL Server exercises the real <c>SELECT SCHEMA_NAME()</c> + <c>INFORMATION_SCHEMA</c>
+    ///     path the loader depends on; the SQLite-backed suites prove the logic but not that T-SQL's catalog
+    ///     answers the shape the loader expects.
+    /// </remarks>
+    [Fact]
+    public async Task CatalogGate_realSqlServer_rejectsAnUnknownColumn_andSparesItsNeighbour()
+    {
+        SkipUnlessLive();
+
+        var bogus = Tag("Sql/Line1/Bogus", new JsonObject
+        {
+            ["driver"] = "Sql",
+            ["model"] = "KeyValue",
+            ["table"] = SqlPollServerFixture.Qualified(SqlPollServerFixture.KeyValueTable),
+            ["keyColumn"] = SqlPollServerFixture.KeyColumn,
+            ["keyValue"] = SqlPollServerFixture.PresentKey,
+            ["valueColumn"] = "no_such_column",
+            ["timestampColumn"] = SqlPollServerFixture.TimestampColumn,
+        });
+
+        await using var driver = await StartAsync(
+            KeyValue("Sql/Line1/Speed", SqlPollServerFixture.PresentKey), bogus);
+
+        // An authoring typo is not a database fault: the driver stays Healthy.
+        driver.GetHealth().State.ShouldBe(DriverState.Healthy);
+
+        var snapshots = await driver.ReadAsync(
+            ["Sql/Line1/Speed", "Sql/Line1/Bogus"], TestContext.Current.CancellationToken);
+
+        SqlStatusCodes.IsGood(snapshots[0].StatusCode).ShouldBeTrue();
+        snapshots[1].StatusCode.ShouldBe(SqlStatusCodes.BadNodeIdUnknown);
+    }
+
+    /// <summary>
+    ///     T-SQL object names are case-insensitive under the default collation, so a case-variant tag has
+    ///     always been valid and must keep working — the gate substitutes the catalog's spelling rather than
+    ///     rejecting the operator's.
+    /// </summary>
+    [Fact]
+    public async Task CatalogGate_realSqlServer_acceptsACaseVariantIdentifierAndStillReads()
+    {
+        SkipUnlessLive();
+
+        var upper = Tag("Sql/Line1/Speed", new JsonObject
+        {
+            ["driver"] = "Sql",
+            ["model"] = "KeyValue",
+            ["table"] = SqlPollServerFixture.Qualified(SqlPollServerFixture.KeyValueTable).ToUpperInvariant(),
+            ["keyColumn"] = SqlPollServerFixture.KeyColumn.ToUpperInvariant(),
+            ["keyValue"] = SqlPollServerFixture.PresentKey,
+            ["valueColumn"] = SqlPollServerFixture.ValueColumn.ToUpperInvariant(),
+            ["timestampColumn"] = SqlPollServerFixture.TimestampColumn.ToUpperInvariant(),
+        });
+
+        await using var driver = await StartAsync(upper);
+
+        var snapshot = (await driver.ReadAsync(["Sql/Line1/Speed"], TestContext.Current.CancellationToken))
+            .ShouldHaveSingleItem();
+        SqlStatusCodes.IsGood(snapshot.StatusCode).ShouldBeTrue();
+    }
+
+    /// <summary>
+    ///     A cross-database name cannot be validated from this connection's catalog, so it is refused rather
+    ///     than quoted into a query — the documented v1 limitation, asserted so it stays deliberate.
+    /// </summary>
+    [Fact]
+    public async Task CatalogGate_realSqlServer_rejectsAThreePartName()
+    {
+        SkipUnlessLive();
+
+        var threePart = Tag("Sql/Line1/Remote", new JsonObject
+        {
+            ["driver"] = "Sql",
+            ["model"] = "KeyValue",
+            ["table"] = $"otherdb.{SqlPollServerFixture.Qualified(SqlPollServerFixture.KeyValueTable)}",
+            ["keyColumn"] = SqlPollServerFixture.KeyColumn,
+            ["keyValue"] = SqlPollServerFixture.PresentKey,
+            ["valueColumn"] = SqlPollServerFixture.ValueColumn,
+        });
+
+        await using var driver = await StartAsync(threePart);
+
+        (await driver.ReadAsync(["Sql/Line1/Remote"], TestContext.Current.CancellationToken))
+            .ShouldHaveSingleItem().StatusCode.ShouldBe(SqlStatusCodes.BadNodeIdUnknown);
+    }
+
     /// <summary>Skips the calling test when the live-server gate is not configured or not reachable.</summary>
     private void SkipUnlessLive()
     {

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql.Tests/SqlCatalogGateDriverTests.cs

@@ -0,0 +1,354 @@
+using System.Globalization;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Abstractions;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+using ZB.MOM.WW.OtOpcUa.Driver.Sql.Contracts;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Sql.Tests;
+
+/// <summary>
+///     The design §8.1 catalog gate end-to-end through <see cref="SqlDriver"/>, against the real SQLite
+///     catalog the poll fixture creates — real <c>ListSchemas</c>/<c>ListTables</c>/<c>ListColumns</c>
+///     round-trips, not a hand-built <see cref="SqlCatalog"/>.
+///     <para><b>The two facts that matter most here</b> are the ones a pure unit test cannot show: that a
+///     rejected tag still <em>has a node</em> and reads <c>BadNodeIdUnknown</c> (rather than silently
+///     vanishing from the address space), and that a catalog the driver cannot read faults Initialize instead
+///     of rejecting every tag.</para>
+/// </summary>
+public sealed class SqlCatalogGateDriverTests
+{
+    private const string DriverInstanceId = "sql-gate";
+    private const string ConfigJson = """{"provider":"SqlServer"}""";
+
+    [Fact]
+    public async Task A_tag_naming_a_real_table_and_columns_polls_normally()
+    {
+        using var fixture = new SqlitePollFixture();
+        await using var driver = NewDriver(fixture, KvEntry("Speed", SqlitePollFixture.PresentKey));
+
+        await driver.InitializeAsync(ConfigJson, CancellationToken.None);
+
+        driver.GetHealth().State.ShouldBe(DriverState.Healthy);
+        var snapshot = (await driver.ReadAsync(["Speed"], CancellationToken.None)).ShouldHaveSingleItem();
+        SqlStatusCodes.IsGood(snapshot.StatusCode).ShouldBeTrue();
+        snapshot.Value.ShouldBe(SqlitePollFixture.PresentValue);
+    }
+
+    /// <summary>
+    ///     §8.1's specified outcome, in full: the tag is refused by the allow-list, so it never reaches a
+    ///     query — but its node still exists and reads <c>BadNodeIdUnknown</c>. Dropping the node instead would
+    ///     turn a diagnosable Bad quality into a missing address-space entry.
+    /// </summary>
+    [Fact]
+    public async Task A_tag_naming_an_unknown_column_keeps_its_node_and_reads_BadNodeIdUnknown()
+    {
+        using var fixture = new SqlitePollFixture();
+        await using var driver = NewDriver(
+            fixture,
+            KvEntry("Speed", SqlitePollFixture.PresentKey),
+            KvEntry("Bogus", SqlitePollFixture.PresentKey, valueColumn: "no_such_column"));
+
+        await driver.InitializeAsync(ConfigJson, CancellationToken.None);
+
+        // The driver is healthy: an authoring typo is not a database fault.
+        driver.GetHealth().State.ShouldBe(DriverState.Healthy);
+
+        // The node is still materialized...
+        var capture = new CapturingBuilder();
+        await ((ITagDiscovery)driver).DiscoverAsync(capture, CancellationToken.None);
+        capture.Variables.Select(v => v.Info.FullName).ShouldBe(["Speed", "Bogus"], ignoreOrder: true);
+
+        // ...and it is the rejected tag — and only it — that reads BadNodeIdUnknown.
+        var snapshots = await driver.ReadAsync(["Speed", "Bogus"], CancellationToken.None);
+        SqlStatusCodes.IsGood(snapshots[0].StatusCode).ShouldBeTrue();
+        snapshots[1].StatusCode.ShouldBe(SqlStatusCodes.BadNodeIdUnknown);
+    }
+
+    [Fact]
+    public async Task A_tag_naming_an_unknown_table_reads_BadNodeIdUnknown()
+    {
+        using var fixture = new SqlitePollFixture();
+        await using var driver = NewDriver(
+            fixture, KvEntry("Bogus", SqlitePollFixture.PresentKey, table: "NoSuchTable"));
+
+        await driver.InitializeAsync(ConfigJson, CancellationToken.None);
+
+        (await driver.ReadAsync(["Bogus"], CancellationToken.None))
+            .ShouldHaveSingleItem().StatusCode.ShouldBe(SqlStatusCodes.BadNodeIdUnknown);
+    }
+
+    /// <summary>
+    ///     The injection shape #496 exists to close. Before the gate, this name was bracket-quoted into a real
+    ///     query that failed only once the connection was open; now it never reaches a query at all.
+    /// </summary>
+    [Fact]
+    public async Task A_hostile_table_name_never_reaches_a_query()
+    {
+        using var fixture = new SqlitePollFixture();
+        var logger = new CapturingLogger();
+        await using var driver = NewDriver(
+            fixture, logger,
+            KvEntry("Evil", SqlitePollFixture.PresentKey, table: "TagValues\"; DROP TABLE TagValues--"));
+
+        await driver.InitializeAsync(ConfigJson, CancellationToken.None);
+
+        (await driver.ReadAsync(["Evil"], CancellationToken.None))
+            .ShouldHaveSingleItem().StatusCode.ShouldBe(SqlStatusCodes.BadNodeIdUnknown);
+
+        // The fixture's table is untouched — proven by a second tag still reading through it.
+        await using var honest = NewDriver(fixture, KvEntry("Speed", SqlitePollFixture.PresentKey));
+        await honest.InitializeAsync(ConfigJson, CancellationToken.None);
+        var snapshot = (await honest.ReadAsync(["Speed"], CancellationToken.None)).ShouldHaveSingleItem();
+        SqlStatusCodes.IsGood(snapshot.StatusCode).ShouldBeTrue();
+
+        logger.Entries.ShouldContain(e =>
+            e.Level == LogLevel.Warning && e.Message.Contains("rejected by the catalog gate", StringComparison.Ordinal));
+    }
+
+    /// <summary>
+    ///     A node that goes Bad with nothing in the log is unsupportable, so every drop names the tag, the
+    ///     field and the reason.
+    /// </summary>
+    [Fact]
+    public async Task Every_rejection_is_logged_with_the_tag_the_field_and_the_reason()
+    {
+        using var fixture = new SqlitePollFixture();
+        var logger = new CapturingLogger();
+        await using var driver = NewDriver(
+            fixture, logger, KvEntry("Bogus", SqlitePollFixture.PresentKey, valueColumn: "num_valeu"));
+
+        await driver.InitializeAsync(ConfigJson, CancellationToken.None);
+
+        var warning = logger.Entries
+            .Where(e => e.Level == LogLevel.Warning)
+            .Select(e => e.Message)
+            .ShouldHaveSingleItem();
+        warning.ShouldContain("Bogus");
+        warning.ShouldContain(nameof(SqlTagDefinition.ValueColumn));
+        warning.ShouldContain("num_valeu");
+    }
+
+    /// <summary>
+    ///     Case-insensitive authoring has always worked on SQL Server's default collation, so the gate must
+    ///     accept it — and it substitutes the catalog's spelling, which is what makes the emitted SQL carry
+    ///     catalog strings rather than operator input.
+    /// </summary>
+    [Fact]
+    public async Task A_case_variant_identifier_is_accepted_and_polls()
+    {
+        using var fixture = new SqlitePollFixture();
+        await using var driver = NewDriver(
+            fixture,
+            KvEntry(
+                "Speed", SqlitePollFixture.PresentKey,
+                table: SqlitePollFixture.KeyValueTable.ToUpperInvariant(),
+                valueColumn: SqlitePollFixture.ValueColumn.ToUpperInvariant()));
+
+        await driver.InitializeAsync(ConfigJson, CancellationToken.None);
+
+        var snapshot = (await driver.ReadAsync(["Speed"], CancellationToken.None)).ShouldHaveSingleItem();
+        SqlStatusCodes.IsGood(snapshot.StatusCode).ShouldBeTrue();
+        snapshot.Value.ShouldBe(SqlitePollFixture.PresentValue);
+    }
+
+    /// <summary>
+    ///     A driver with nothing authored has nothing to validate; issuing catalog queries to prove that would
+    ///     be a round-trip that can only fail.
+    /// </summary>
+    [Fact]
+    public async Task A_driver_with_no_authored_tags_initializes_without_touching_the_catalog()
+    {
+        using var fixture = new SqlitePollFixture();
+        await using var driver = NewDriver(fixture);
+
+        await driver.InitializeAsync(ConfigJson, CancellationToken.None);
+
+        driver.GetHealth().State.ShouldBe(DriverState.Healthy);
+    }
+
+    /// <summary>
+    ///     <b>The fail-closed rule.</b> A catalog that cannot be read is the ABSENCE of evidence about the
+    ///     tags, not evidence against them. Rejecting every tag would serve a confidently-empty address space
+    ///     and send the operator hunting typos that do not exist; faulting Initialize instead lands
+    ///     <c>DriverInstanceActor</c> in Reconnecting with its retry timer running.
+    /// </summary>
+    [Fact]
+    public async Task A_catalog_that_cannot_be_read_faults_Initialize_rather_than_rejecting_every_tag()
+    {
+        using var fixture = new SqlitePollFixture();
+        await using var driver = new SqlDriver(
+            new SqlDriverOptions
+            {
+                RawTags = [KvEntry("Speed", SqlitePollFixture.PresentKey)],
+                OperationTimeout = TimeSpan.FromSeconds(15),
+                CommandTimeout = TimeSpan.FromSeconds(10),
+            },
+            DriverInstanceId,
+            new CatalogSqlOverride("SELECT this is not valid sql"),
+            fixture.ConnectionString,
+            factory: fixture.Factory,
+            logger: NullLogger<SqlDriver>.Instance);
+
+        var thrown = await Should.ThrowAsync<InvalidOperationException>(
+            async () => await driver.InitializeAsync(ConfigJson, CancellationToken.None));
+
+        // The operator surface names the stage that actually failed — "reached it but could not read the
+        // catalog" and "could not reach it" send an operator to different systems.
+        thrown.Message.ShouldContain("catalog");
+        driver.GetHealth().State.ShouldBe(DriverState.Faulted);
+    }
+
+    /// <summary>
+    ///     Zero visible schemas is a grant problem, not an empty database, so it must fault rather than reject
+    ///     every tag for an authoring fault the operator does not have.
+    /// </summary>
+    [Fact]
+    public async Task A_catalog_reporting_no_schemas_at_all_faults_Initialize()
+    {
+        using var fixture = new SqlitePollFixture();
+        await using var driver = new SqlDriver(
+            new SqlDriverOptions
+            {
+                RawTags = [KvEntry("Speed", SqlitePollFixture.PresentKey)],
+                OperationTimeout = TimeSpan.FromSeconds(15),
+                CommandTimeout = TimeSpan.FromSeconds(10),
+            },
+            DriverInstanceId,
+            new CatalogSqlOverride("SELECT 'x' AS TABLE_SCHEMA WHERE 1 = 0"),
+            fixture.ConnectionString,
+            factory: fixture.Factory,
+            logger: NullLogger<SqlDriver>.Instance);
+
+        await Should.ThrowAsync<InvalidOperationException>(
+            async () => await driver.InitializeAsync(ConfigJson, CancellationToken.None));
+
+        driver.GetHealth().State.ShouldBe(DriverState.Faulted);
+    }
+
+    // ---- helpers ----
+
+    /// <summary>
+    ///     Delegates every member to <see cref="SqliteDialect"/> except <see cref="ListSchemasSql"/>, so the
+    ///     catalog-load failure modes can be driven against an otherwise-real dialect.
+    /// </summary>
+    /// <remarks>
+    ///     A decorator rather than a subclass: <see cref="SqliteDialect"/> is sealed, and even if it were not,
+    ///     <c>new</c>-hiding a property would leave interface dispatch calling the base — the substitution
+    ///     would silently not happen and both tests below would pass for the wrong reason.
+    /// </remarks>
+    private sealed class CatalogSqlOverride(string listSchemasSql) : ISqlDialect
+    {
+        private static readonly SqliteDialect Inner = new();
+
+        public SqlProvider Provider => Inner.Provider;
+
+        public System.Data.Common.DbProviderFactory Factory => Inner.Factory;
+
+        public string LivenessSql => Inner.LivenessSql;
+
+        public string SingleRowLimitPrefix => Inner.SingleRowLimitPrefix;
+
+        public string SingleRowLimitSuffix => Inner.SingleRowLimitSuffix;
+
+        public string ListSchemasSql { get; } = listSchemasSql;
+
+        public string DefaultSchemaSql => Inner.DefaultSchemaSql;
+
+        public string ListTablesSql => Inner.ListTablesSql;
+
+        public string ListColumnsSql => Inner.ListColumnsSql;
+
+        public string QuoteIdentifier(string ident) => Inner.QuoteIdentifier(ident);
+
+        public DriverDataType MapColumnType(string sqlDataType) => Inner.MapColumnType(sqlDataType);
+    }
+
+    private static SqlDriver NewDriver(SqlitePollFixture fixture, params RawTagEntry[] rawTags)
+        => NewDriver(fixture, new CapturingLogger(), rawTags);
+
+    private static SqlDriver NewDriver(
+        SqlitePollFixture fixture, CapturingLogger logger, params RawTagEntry[] rawTags)
+        => new(
+            new SqlDriverOptions
+            {
+                RawTags = rawTags,
+                OperationTimeout = TimeSpan.FromSeconds(15),
+                CommandTimeout = TimeSpan.FromSeconds(10),
+            },
+            DriverInstanceId,
+            new SqliteDialect(),
+            fixture.ConnectionString,
+            factory: fixture.Factory,
+            logger: logger);
+
+    /// <summary>One authored raw tag, with the table and value column overridable so the gate can be exercised.</summary>
+    private static RawTagEntry KvEntry(
+        string rawPath,
+        string keyValue,
+        string? table = null,
+        string? valueColumn = null)
+        => new(rawPath, string.Create(CultureInfo.InvariantCulture, $$"""
+            {
+              "driver": "Sql",
+              "model": "KeyValue",
+              "table": "{{(table ?? SqlitePollFixture.KeyValueTable).Replace("\"", "\\\"", StringComparison.Ordinal)}}",
+              "keyColumn": "{{SqlitePollFixture.KeyColumn}}",
+              "keyValue": "{{keyValue}}",
+              "valueColumn": "{{valueColumn ?? SqlitePollFixture.ValueColumn}}",
+              "timestampColumn": "{{SqlitePollFixture.TimestampColumn}}"
+            }
+            """), WriteIdempotent: false);
+
+    /// <summary>Records everything the driver streams into the address space.</summary>
+    private sealed class CapturingBuilder : IAddressSpaceBuilder
+    {
+        /// <summary>The variables registered, in order.</summary>
+        public List<(string BrowseName, DriverAttributeInfo Info)> Variables { get; } = [];
+
+        public IAddressSpaceBuilder Folder(string browseName, string displayName) => this;
+
+        public IVariableHandle Variable(string browseName, string displayName, DriverAttributeInfo attributeInfo)
+        {
+            Variables.Add((browseName, attributeInfo));
+            return new Handle(attributeInfo.FullName);
+        }
+
+        public void AddProperty(string browseName, DriverDataType dataType, object? value) { }
+
+        private sealed class Handle(string fullReference) : IVariableHandle
+        {
+            public string FullReference => fullReference;
+
+            public IAlarmConditionSink MarkAsAlarmCondition(AlarmConditionInfo info) => new Sink();
+
+            private sealed class Sink : IAlarmConditionSink
+            {
+                public void OnTransition(AlarmEventArgs args) { }
+            }
+        }
+    }
+
+    /// <summary>Records every log record, level + rendered message.</summary>
+    private sealed class CapturingLogger : ILogger<SqlDriver>
+    {
+        public List<(LogLevel Level, string Message)> Entries { get; } = [];
+
+        public IDisposable BeginScope<TState>(TState state) where TState : notnull => NullScope.Instance;
+
+        public bool IsEnabled(LogLevel logLevel) => true;
+
+        public void Log<TState>(
+            LogLevel logLevel, EventId eventId, TState state, Exception? exception,
+            Func<TState, Exception?, string> formatter)
+            => Entries.Add((logLevel, formatter(state, exception)));
+
+        private sealed class NullScope : IDisposable
+        {
+            public static NullScope Instance { get; } = new();
+
+            public void Dispose() { }
+        }
+    }
+}

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql.Tests/SqlCatalogGateTests.cs

@@ -0,0 +1,316 @@
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Driver.Sql.Contracts;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Sql.Tests;
+
+/// <summary>
+///     The design §8.1 catalog gate (Gitea #496), tested as a pure function over a hand-built
+///     <see cref="SqlCatalog"/>. The end-to-end behaviour against a real catalog — and the proof that a
+///     rejected tag keeps its node and publishes <c>BadNodeIdUnknown</c> — lives in
+///     <see cref="SqlCatalogGateDriverTests"/>.
+/// </summary>
+public sealed class SqlCatalogGateTests
+{
+    private static readonly SqliteDialect Dialect = new();
+
+    /// <summary>A catalog with one schema, two relations, and deliberately mixed-case column spellings.</summary>
+    private static SqlCatalog Catalog(string defaultSchema = "dbo") => new(
+        defaultSchema,
+        ["dbo", "mes"],
+        new Dictionary<string, IReadOnlyList<string>>(StringComparer.Ordinal)
+        {
+            ["dbo"] = ["TagValues", "LatestStatus"],
+            ["mes"] = ["Orders"],
+        },
+        new Dictionary<string, IReadOnlyList<string>>(StringComparer.Ordinal)
+        {
+            ["dbo.TagValues"] = ["tag_name", "num_value", "sample_ts"],
+            ["dbo.LatestStatus"] = ["station_id", "oven_temp", "pressure", "sample_ts"],
+            ["mes.Orders"] = ["order_id", "qty"],
+        });
+
+    private static SqlTagDefinition KeyValueTag(
+        string table = "dbo.TagValues",
+        string keyColumn = "tag_name",
+        string valueColumn = "num_value",
+        string? timestampColumn = "sample_ts") =>
+        new("plant/sql/Speed", SqlTagModel.KeyValue, table,
+            KeyColumn: keyColumn, KeyValue: "Line1.Speed",
+            ValueColumn: valueColumn, TimestampColumn: timestampColumn);
+
+    private static SqlCatalogGateResult Apply(params SqlTagDefinition[] tags) =>
+        SqlCatalogGate.Apply(tags, Catalog(), Dialect);
+
+    [Fact]
+    public void A_fully_resolvable_tag_is_accepted()
+    {
+        var result = Apply(KeyValueTag());
+
+        result.Rejected.ShouldBeEmpty();
+        result.Accepted.Count.ShouldBe(1);
+    }
+
+    /// <summary>
+    ///     The heart of §8.1: what reaches the planner must be a string the catalog gave us, not the string an
+    ///     operator typed. Authoring every identifier in the wrong case proves the substitution actually
+    ///     happens rather than the input merely being waved through.
+    /// </summary>
+    [Fact]
+    public void Accepted_identifiers_are_rewritten_to_the_catalogs_own_spelling()
+    {
+        var authored = KeyValueTag(
+            table: "DBO.TAGVALUES", keyColumn: "TAG_NAME", valueColumn: "Num_Value", timestampColumn: "SAMPLE_TS");
+
+        var accepted = Apply(authored).Accepted.ShouldHaveSingleItem();
+
+        accepted.Table.ShouldBe("dbo.TagValues");
+        accepted.KeyColumn.ShouldBe("tag_name");
+        accepted.ValueColumn.ShouldBe("num_value");
+        accepted.TimestampColumn.ShouldBe("sample_ts");
+        // Identity and bound VALUES are untouched — the gate rewrites identifiers only.
+        accepted.Name.ShouldBe(authored.Name);
+        accepted.KeyValue.ShouldBe(authored.KeyValue);
+    }
+
+    [Fact]
+    public void An_unqualified_table_resolves_in_the_default_schema()
+    {
+        var accepted = Apply(KeyValueTag(table: "TagValues")).Accepted.ShouldHaveSingleItem();
+
+        accepted.Table.ShouldBe("dbo.TagValues");
+    }
+
+    /// <summary>
+    ///     Guessing <c>dbo</c> would be a silent lie on an estate that maps service accounts to their own
+    ///     default schema, so the gate must resolve an unqualified name in whatever schema the server reports.
+    /// </summary>
+    [Fact]
+    public void An_unqualified_table_follows_a_non_dbo_default_schema()
+    {
+        var catalog = Catalog(defaultSchema: "mes");
+
+        var result = SqlCatalogGate.Apply([KeyValueTag(table: "Orders", keyColumn: "order_id", valueColumn: "qty", timestampColumn: null)], catalog, Dialect);
+
+        result.Accepted.ShouldHaveSingleItem().Table.ShouldBe("mes.Orders");
+    }
+
+    [Fact]
+    public void An_unknown_table_rejects_the_tag()
+    {
+        var rejection = Apply(KeyValueTag(table: "dbo.NoSuchTable")).Rejected.ShouldHaveSingleItem();
+
+        rejection.RawPath.ShouldBe("plant/sql/Speed");
+        rejection.Field.ShouldBe(nameof(SqlTagDefinition.Table));
+        rejection.Reason.ShouldContain("NoSuchTable");
+    }
+
+    [Fact]
+    public void An_unknown_schema_rejects_the_tag()
+    {
+        var rejection = Apply(KeyValueTag(table: "nope.TagValues")).Rejected.ShouldHaveSingleItem();
+
+        rejection.Field.ShouldBe(nameof(SqlTagDefinition.Table));
+        rejection.Reason.ShouldContain("nope");
+    }
+
+    [Fact]
+    public void An_unknown_column_rejects_the_tag_and_names_the_field()
+    {
+        var rejection = Apply(KeyValueTag(valueColumn: "no_such_column")).Rejected.ShouldHaveSingleItem();
+
+        rejection.Field.ShouldBe(nameof(SqlTagDefinition.ValueColumn));
+        rejection.Reason.ShouldContain("no_such_column");
+        rejection.Reason.ShouldContain("dbo.TagValues");
+    }
+
+    /// <summary>
+    ///     A table in the right catalog but the wrong schema must not resolve — otherwise the gate would
+    ///     allow-list a column set from a relation the query will never read.
+    /// </summary>
+    [Fact]
+    public void A_table_from_another_schema_does_not_resolve_unqualified()
+    {
+        var rejection = Apply(KeyValueTag(table: "Orders", keyColumn: "order_id", valueColumn: "qty", timestampColumn: null))
+            .Rejected.ShouldHaveSingleItem();
+
+        rejection.Field.ShouldBe(nameof(SqlTagDefinition.Table));
+    }
+
+    /// <summary>
+    ///     A cross-database or linked-server name addresses a catalog this connection cannot enumerate, so it
+    ///     cannot be allow-listed. Rejecting is the fail-closed answer, and the message says what to do instead.
+    /// </summary>
+    [Fact]
+    public void A_three_part_name_is_rejected_with_an_actionable_message()
+    {
+        var rejection = Apply(KeyValueTag(table: "otherdb.dbo.TagValues")).Rejected.ShouldHaveSingleItem();
+
+        rejection.Field.ShouldBe(nameof(SqlTagDefinition.Table));
+        rejection.Reason.ShouldContain("3-part");
+        rejection.Reason.ShouldContain("view");
+    }
+
+    /// <summary>
+    ///     The injection shape the whole gate exists for: a hostile identifier must be refused by the
+    ///     allow-list, not merely quoted into a query against a nonexistent object.
+    /// </summary>
+    [Theory]
+    [InlineData("TagValues]; DROP TABLE TagValues--")]
+    [InlineData("'; DROP TABLE TagValues--")]
+    [InlineData("TagValues WHERE 1=1 OR 1=1")]
+    public void A_hostile_table_name_is_rejected_by_the_allow_list(string table)
+    {
+        Apply(KeyValueTag(table: table)).Rejected.ShouldHaveSingleItem()
+            .Field.ShouldBe(nameof(SqlTagDefinition.Table));
+    }
+
+    [Theory]
+    [InlineData("num_value]; DROP TABLE TagValues--")]
+    [InlineData("(SELECT password FROM users)")]
+    public void A_hostile_column_name_is_rejected_by_the_allow_list(string column)
+    {
+        Apply(KeyValueTag(valueColumn: column)).Rejected.ShouldHaveSingleItem()
+            .Field.ShouldBe(nameof(SqlTagDefinition.ValueColumn));
+    }
+
+    /// <summary>
+    ///     A name carrying a control or Unicode format character cannot be safely rendered into a log line
+    ///     (the Trojan-Source class, CVE-2021-42574), so the gate rejects it <em>without echoing it</em> — the
+    ///     charset check runs before the catalog lookup precisely so no such string can reach a message.
+    /// </summary>
+    /// <remarks>
+    ///     Driven against <see cref="SqlServerDialect"/>, not the test-only <see cref="SqliteDialect"/>: the
+    ///     charset rules belong to the dialect (the gate delegates to
+    ///     <see cref="ISqlDialect.QuoteIdentifier"/> rather than duplicating them), and SQLite's rules
+    ///     deliberately stop at control characters. Asserting SQL Server's rules means using SQL Server's
+    ///     dialect — the first draft of this test asserted them against SQLite's and failed for that reason.
+    /// </remarks>
+    [Theory]
+    [InlineData("num\u0000value")]   // Cc — embedded NUL
+    [InlineData("num\u0009value")]   // Cc — tab; truncates or corrupts a logged statement
+    [InlineData("num\u202Evalue")]   // Cf — right-to-left override
+    [InlineData("num\u200Bvalue")]   // Cf — zero-width space
+    public void An_unrenderable_identifier_is_rejected_without_being_echoed(string column)
+    {
+        var result = SqlCatalogGate.Apply(
+            [KeyValueTag(valueColumn: column)], Catalog(), new SqlServerDialect());
+
+        var rejection = result.Rejected.ShouldHaveSingleItem();
+        rejection.Field.ShouldBe(nameof(SqlTagDefinition.ValueColumn));
+        rejection.Reason.ShouldContain("withheld");
+        rejection.Reason.ShouldNotContain(column);
+    }
+
+    /// <summary>
+    ///     An over-long name cannot name a real object and is likewise withheld, rather than pasting an
+    ///     unbounded slab of operator input into a log line.
+    /// </summary>
+    [Fact]
+    public void An_over_long_identifier_is_rejected_without_being_echoed()
+    {
+        var column = new string('x', SqlServerDialect.MaxIdentifierLength + 1);
+
+        var result = SqlCatalogGate.Apply(
+            [KeyValueTag(valueColumn: column)], Catalog(), new SqlServerDialect());
+
+        result.Rejected.ShouldHaveSingleItem().Reason.ShouldContain("withheld");
+    }
+
+    /// <summary>
+    ///     The complement, and the reason the charset check is not simply "withhold everything": a name that
+    ///     IS safely renderable gets echoed, because an operator hunting a typo has to see what they wrote.
+    /// </summary>
+    [Fact]
+    public void A_renderable_but_unknown_identifier_IS_echoed_so_the_typo_is_findable()
+    {
+        var rejection = Apply(KeyValueTag(valueColumn: "num_valeu")).Rejected.ShouldHaveSingleItem();
+
+        rejection.Reason.ShouldContain("num_valeu");
+        rejection.Reason.ShouldNotContain("withheld");
+    }
+
+    /// <summary>
+    ///     On a case-sensitive collation a relation may legitimately carry both <c>Value</c> and <c>value</c>.
+    ///     Picking one would publish a different column's data under the operator's node, so the only safe
+    ///     answer is to refuse — but an EXACT match must still win, or a valid config would break.
+    /// </summary>
+    [Fact]
+    public void An_ambiguous_case_insensitive_column_match_is_rejected_but_an_exact_match_still_wins()
+    {
+        var catalog = new SqlCatalog(
+            "dbo",
+            ["dbo"],
+            new Dictionary<string, IReadOnlyList<string>>(StringComparer.Ordinal) { ["dbo"] = ["T"] },
+            new Dictionary<string, IReadOnlyList<string>>(StringComparer.Ordinal)
+            {
+                ["dbo.T"] = ["k", "Value", "value"],
+            });
+
+        var ambiguous = new SqlTagDefinition(
+            "p/Ambiguous", SqlTagModel.KeyValue, "dbo.T",
+            KeyColumn: "k", KeyValue: "x", ValueColumn: "VALUE");
+        SqlCatalogGate.Apply([ambiguous], catalog, Dialect).Rejected.ShouldHaveSingleItem()
+            .Field.ShouldBe(nameof(SqlTagDefinition.ValueColumn));
+
+        var exact = ambiguous with { Name = "p/Exact", ValueColumn = "value" };
+        SqlCatalogGate.Apply([exact], catalog, Dialect).Accepted.ShouldHaveSingleItem()
+            .ValueColumn.ShouldBe("value");
+    }
+
+    /// <summary>
+    ///     One operator typo must not stop the other tags on the same database — the same rule the tag-table
+    ///     build already follows for a malformed blob.
+    /// </summary>
+    [Fact]
+    public void A_rejected_tag_does_not_take_its_healthy_neighbours_with_it()
+    {
+        var good = KeyValueTag() with { Name = "plant/sql/Good" };
+        var bad = KeyValueTag(valueColumn: "typo") with { Name = "plant/sql/Bad" };
+
+        var result = Apply(good, bad);
+
+        result.Accepted.ShouldHaveSingleItem().Name.ShouldBe("plant/sql/Good");
+        result.Rejected.ShouldHaveSingleItem().RawPath.ShouldBe("plant/sql/Bad");
+    }
+
+    /// <summary>Every identifier-bearing field is checked, not just the two the key-value model happens to use.</summary>
+    [Fact]
+    public void The_wide_row_models_identifier_fields_are_validated_too()
+    {
+        var selectorTypo = new SqlTagDefinition(
+            "p/Oven", SqlTagModel.WideRow, "dbo.LatestStatus",
+            ColumnName: "oven_temp", RowSelectorColumn: "no_such_selector", RowSelectorValue: "7");
+        Apply(selectorTypo).Rejected.ShouldHaveSingleItem()
+            .Field.ShouldBe(nameof(SqlTagDefinition.RowSelectorColumn));
+
+        var orderTypo = new SqlTagDefinition(
+            "p/Newest", SqlTagModel.WideRow, "dbo.LatestStatus",
+            ColumnName: "oven_temp", RowSelectorTopByTimestamp: "no_such_ts");
+        Apply(orderTypo).Rejected.ShouldHaveSingleItem()
+            .Field.ShouldBe(nameof(SqlTagDefinition.RowSelectorTopByTimestamp));
+
+        var columnTypo = new SqlTagDefinition(
+            "p/Bad", SqlTagModel.WideRow, "dbo.LatestStatus",
+            ColumnName: "no_such_column", RowSelectorColumn: "station_id", RowSelectorValue: "7");
+        Apply(columnTypo).Rejected.ShouldHaveSingleItem()
+            .Field.ShouldBe(nameof(SqlTagDefinition.ColumnName));
+
+        var ok = new SqlTagDefinition(
+            "p/Ok", SqlTagModel.WideRow, "dbo.LatestStatus",
+            ColumnName: "OVEN_TEMP", RowSelectorColumn: "STATION_ID", RowSelectorValue: "7");
+        var accepted = Apply(ok).Accepted.ShouldHaveSingleItem();
+        accepted.ColumnName.ShouldBe("oven_temp");
+        accepted.RowSelectorColumn.ShouldBe("station_id");
+        accepted.RowSelectorValue.ShouldBe("7");   // a bound value, never canonicalized
+    }
+
+    /// <summary>An absent optional identifier is not a rejection — only a present, unresolvable one is.</summary>
+    [Fact]
+    public void An_absent_optional_timestamp_column_is_left_alone()
+    {
+        var accepted = Apply(KeyValueTag(timestampColumn: null)).Accepted.ShouldHaveSingleItem();
+
+        accepted.TimestampColumn.ShouldBeNull();
+    }
+}

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql.Tests/SqlDriverTests.cs

@@ -424,6 +424,27 @@ public sealed class SqlDriverTests
         driver.GetHealth().State.ShouldBe(DriverState.Degraded);
     }
 
+    [Fact]
+    public void HandlePollError_forANonDbExceptionCarryingCredentials_degradesWithoutLeakingThem()
+    {
+        // The residual C1 leg HandlePollError owns: a NON-DbException raised from provider interaction —
+        // canonically the ArgumentException a malformed connection string's keyword parser throws, echoing
+        // credential fragments (the exact unquoted-';'-in-password vector this whole fix exists for). It is
+        // not the DbException class ReadAsync owns, so it reaches Degrade — and must arrive TYPE-only, never
+        // ex.Message. Pre-fix this degraded with the raw message and leaked the token.
+        using var fixture = new SqlitePollFixture();
+        var driver = NewDriver(fixture, KvEntry("Speed", SqlitePollFixture.PresentKey));
+
+        driver.HandlePollError(new ArgumentException(
+            "Keyword not supported: 'secrettail;connect timeout'. Password=" + SecretToken));
+
+        var health = driver.GetHealth();
+        health.State.ShouldBe(DriverState.Degraded);
+        health.LastError.ShouldNotBeNull();
+        health.LastError.ShouldNotContain(SecretToken);                 // never the message text
+        health.LastError.ShouldContain(nameof(ArgumentException));      // but still actionable (the type)
+    }
+
     // ---- I2: a late poll cannot un-fault a Faulted driver ----
 
     [Fact]

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql.Tests/SqlInjectionRegressionTests.cs

@@ -12,16 +12,19 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.Sql.Tests;
 ///     <em>identifier</em> — which cannot be parameterized in SQL — is dialect-quoted so a hostile one becomes
 ///     an inert reference to a nonexistent object rather than executable text. If these pass, a malicious tag
 ///     cannot alter the database; the seed table is intact after every hostile poll.
-///     <para><b>Scope note — what this suite does NOT assume.</b> Design §8.1 also specifies a catalog gate:
-///     validate every authored table/column against <c>INFORMATION_SCHEMA</c> before quoting it, so an unknown
-///     identifier <em>rejects the tag</em>. <b>No such gate exists in the driver yet</b> (see the "Not yet
-///     implemented" note on <see cref="ISqlDialect"/>), and no task in this workstream builds one. So a hostile
-///     identifier here is <b>not</b> rejected as <c>BadNodeIdUnknown</c> — it is bracket-/double-quoted into a
-///     single nonexistent identifier, the query then fails after the connection opened, and the tag Bad-codes
-///     as a query failure (<see cref="SqlStatusCodes.BadCommunicationError"/>). This suite proves the payload
-///     is <em>inert</em> — it does not execute and the table survives — which is the guarantee the code
-///     actually makes. The catalog gate is a separate follow-up; a test that pretended it existed would be
-///     asserting fiction.</para>
+///     <para><b>Scope note — this suite deliberately tests the layer BELOW the catalog gate.</b> Design
+///     §8.1's catalog gate now exists (Gitea #496): <see cref="SqlCatalogGate"/> validates every authored
+///     table/column against the live catalog at Initialize, so in the assembled driver a hostile identifier
+///     is rejected up front and its tag reads <see cref="SqlStatusCodes.BadNodeIdUnknown"/> — proven by
+///     <c>SqlCatalogGateDriverTests</c>.</para>
+///     <para>The tests here construct a <see cref="SqlPollReader"/> <b>directly</b>, with hand-built
+///     definitions that never pass through the gate, and that is the point: defence in depth is only worth
+///     the name if each layer holds on its own. These assertions pin the <em>quoting backstop</em> — that
+///     even with the allow-list bypassed entirely, a hostile identifier becomes an inert reference to a
+///     nonexistent object, the query fails after the connection opened, the tag Bad-codes as a query failure
+///     (<see cref="SqlStatusCodes.BadCommunicationError"/>), and the seed table survives. Rewriting them to
+///     expect <c>BadNodeIdUnknown</c> would delete the only coverage the backstop has and leave the gate as a
+///     single point of failure.</para>
 /// </summary>
 public sealed class SqlInjectionRegressionTests
 {
@@ -68,9 +71,11 @@ public sealed class SqlInjectionRegressionTests
         using var fixture = new SqlitePollFixture();
         var seedRows = await RowCountAsync(fixture, SqlitePollFixture.KeyValueTable);
 
-        // A table name carrying a statement terminator + DROP. There is NO catalog gate, so this is not
-        // rejected up front — it is quoted into one nonexistent identifier. The query fails (no such table),
-        // the connection having opened, so the tag Bad-codes as a query failure. The DROP never runs.
+        // A table name carrying a statement terminator + DROP. The reader is driven directly, so the
+        // catalog gate never sees it and the quoting backstop is on its own: the name is quoted into one
+        // nonexistent identifier, the query fails (no such table) with the connection already open, so the
+        // tag Bad-codes as a query failure. The DROP never runs. In the assembled driver the gate rejects
+        // this first and the tag reads BadNodeIdUnknown instead — see SqlCatalogGateDriverTests.
         var reader = NewReader(fixture,
             new SqlTagDefinition(
                 Name: "Evil",
@@ -83,7 +88,7 @@ public sealed class SqlInjectionRegressionTests
 
         var snapshots = await reader.ReadAsync(["Evil"], CancellationToken.None);
 
-        // Bad-coded — but as a QUERY failure, not BadNodeIdUnknown (there is no identifier-catalog gate).
+        // Bad-coded as a QUERY failure, not BadNodeIdUnknown — this reader was built without the gate.
         SqlStatusCodes.IsBad(snapshots[0].StatusCode).ShouldBeTrue();
         snapshots[0].StatusCode.ShouldBe(SqlStatusCodes.BadCommunicationError);
         // The load-bearing assertion: the payload did NOT execute. The table and its rows are untouched.

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql.Tests/SqliteDialect.cs

@@ -64,6 +64,12 @@ public sealed class SqliteDialect : ISqlDialect
     /// </summary>
     public string ListSchemasSql => $"SELECT '{MainSchema}' AS TABLE_SCHEMA";
 
+    /// <summary>
+    ///     SQLite has no per-principal default schema, so an unqualified name always resolves in
+    ///     <see cref="MainSchema"/> — the same single schema <see cref="ListSchemasSql"/> reports.
+    /// </summary>
+    public string DefaultSchemaSql => $"SELECT '{MainSchema}'";
+
     /// <summary>
     ///     Tables + views from <c>sqlite_schema</c> (the modern name for <c>sqlite_master</c>), with the
     ///     internal <c>sqlite_*</c> objects filtered out and the type folded onto the

tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/SqlDriverFormContractTests.cs

@@ -0,0 +1,89 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Driver.Sql;
+using ZB.MOM.WW.OtOpcUa.Driver.Sql.Contracts;
+
+namespace ZB.MOM.WW.OtOpcUa.AdminUI.Tests.Uns;
+
+/// <summary>
+/// Guards the AdminUI <c>SqlDriverForm</c>'s driver-config output against the runtime factory that consumes
+/// it. The form is razor (no bUnit here), so these tests pin two things the live verify then confirms:
+/// (1) the exact JSON bytes the form emits for a minimal + fuller config are accepted by the authoritative
+/// reader, <see cref="SqlDriverFactoryExtensions.CreateInstance(string,string)"/>; and (2) the
+/// serialization contract — <c>provider</c> as a NAME string (never an ordinal), camelCase keys, and no
+/// composer-owned <c>rawTags</c> / inert <c>allowWrites</c> leaking into the authored blob. A numeric enum
+/// or a stray connection string is the "authors fine, never reads / leaks a secret" defect class this guards.
+/// </summary>
+public sealed class SqlDriverFormContractTests
+{
+    // The JsonSerializerOptions SqlDriverForm serializes with (camelCase + string enums + omit-nulls).
+    private static readonly JsonSerializerOptions FormOptions = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        UnmappedMemberHandling = JsonUnmappedMemberHandling.Skip,
+        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
+        WriteIndented = false,
+        Converters = { new JsonStringEnumConverter() },
+    };
+
+    // ---- LOAD-BEARING: the exact bytes SqlDriverForm emits must construct a driver through the factory ----
+
+    [Theory]
+    // Minimal valid config: provider + required connectionStringRef only (all timeouts left to the factory).
+    [InlineData("""{"provider":"SqlServer","connectionStringRef":"AdminUiFormTest"}""")]
+    // Fuller config with every optional the form authors (timeouts satisfy operationTimeout > commandTimeout).
+    [InlineData("""{"provider":"SqlServer","connectionStringRef":"AdminUiFormTest","defaultPollInterval":"00:00:05","operationTimeout":"00:00:20","commandTimeout":"00:00:10","maxConcurrentGroups":8,"nullIsBad":true}""")]
+    public void FormEmittedJson_constructs_a_driver_through_the_factory(string formEmittedJson)
+    {
+        var envVar = SqlConnectionStringResolver.EnvironmentVariableFor("AdminUiFormTest");
+        var previous = Environment.GetEnvironmentVariable(envVar);
+        Environment.SetEnvironmentVariable(envVar, "Server=localhost;Database=Test;Trusted_Connection=True;");
+        try
+        {
+            var driver = SqlDriverFactoryExtensions.CreateInstance("adminui-form-test", formEmittedJson);
+            driver.ShouldNotBeNull();
+        }
+        finally
+        {
+            Environment.SetEnvironmentVariable(envVar, previous);
+        }
+    }
+
+    [Fact]
+    public void Factory_rejects_a_blob_missing_connectionStringRef()
+    {
+        // The form marks connectionStringRef required; the factory is the authoritative enforcement.
+        var ex = Should.Throw<InvalidOperationException>(
+            () => SqlDriverFactoryExtensions.CreateInstance("adminui-form-test", """{"provider":"SqlServer"}"""));
+        ex.Message.ShouldContain("connectionStringRef");
+    }
+
+    // ---- serialization contract: enum-by-name, camelCase, no rawTags / allowWrites / null optionals --------
+
+    [Fact]
+    public void Minimal_config_serializes_provider_as_a_name_and_omits_owned_and_null_fields()
+    {
+        // Mirrors SqlDriverForm.FormModel.ToDto() for a minimal config (only the required ref set).
+        var dto = new SqlDriverConfigDto { Provider = SqlProvider.SqlServer, ConnectionStringRef = "MesStaging" };
+
+        var json = JsonSerializer.Serialize(dto, FormOptions);
+
+        json.ShouldBe("""{"provider":"SqlServer","connectionStringRef":"MesStaging"}""");
+        json.ShouldNotContain("\"provider\":0");   // never an ordinal — that faults the string-typed factory read
+        json.ShouldNotContain("rawTags");           // composer-owned; never authored by the form
+        json.ShouldNotContain("allowWrites");       // inert in v1 (read-only); never authored
+        json.ShouldNotContain("defaultPollInterval"); // null optional omitted ⇒ factory default applies
+    }
+
+    [Fact]
+    public void Provider_round_trips_as_the_SqlServer_name()
+    {
+        var json = JsonSerializer.Serialize(
+            new SqlDriverConfigDto { Provider = SqlProvider.SqlServer, ConnectionStringRef = "R" }, FormOptions);
+
+        json.ShouldContain("\"SqlServer\"");
+        JsonSerializer.Deserialize<SqlDriverConfigDto>(json, FormOptions)!.Provider.ShouldBe(SqlProvider.SqlServer);
+    }
+}

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/Drivers/DriverHostActorWriteRoutingTests.cs

@@ -55,11 +55,9 @@ public sealed class DriverHostActorWriteRoutingTests : RuntimeActorTestBase
 
         var actor = SpawnHostAndApply(db, deploymentId, recorder);
 
-        var asker = CreateTestProbe();
         // The node manager passes the FULL ns-qualified id; the host must normalise + resolve it.
-        actor.Tell(new DriverHostActor.RouteNodeWrite($"ns=3;s={UnsNodeId}", 123.0, AddressSpaceRealm.Uns), asker.Ref);
+        RouteWriteUntilAccepted(actor, $"ns=3;s={UnsNodeId}", 123.0, AddressSpaceRealm.Uns);
 
-        asker.ExpectMsg<DriverHostActor.NodeWriteResult>(Timeout).Success.ShouldBeTrue();
         AwaitAssert(() =>
         {
             recorder.Writes.Count.ShouldBe(1);
@@ -79,10 +77,8 @@ public sealed class DriverHostActorWriteRoutingTests : RuntimeActorTestBase
 
         var actor = SpawnHostAndApply(db, deploymentId, recorder);
 
-        var asker = CreateTestProbe();
-        actor.Tell(new DriverHostActor.RouteNodeWrite($"ns=2;s={RawPath}", 456.0, AddressSpaceRealm.Raw), asker.Ref);
+        RouteWriteUntilAccepted(actor, $"ns=2;s={RawPath}", 456.0, AddressSpaceRealm.Raw);
 
-        asker.ExpectMsg<DriverHostActor.NodeWriteResult>(Timeout).Success.ShouldBeTrue();
         AwaitAssert(() =>
         {
             recorder.Writes.Count.ShouldBe(1);
@@ -91,6 +87,48 @@ public sealed class DriverHostActorWriteRoutingTests : RuntimeActorTestBase
         }, duration: Timeout);
     }
 
+    /// <summary>
+    ///     Routes a write, retrying until the host accepts it, and fails with the host's own rejection
+    ///     <c>Reason</c> if it never does.
+    /// </summary>
+    /// <remarks>
+    ///     <para><b>Why a retry rather than a single Tell.</b> <c>ApplyAck</c> — which
+    ///     <see cref="SpawnHostAndApply"/> waits for — marks the end of the <em>apply</em>, not the point at
+    ///     which a write can succeed. Several things still have to happen after it: the spawned child has to
+    ///     finish <c>InitializeAsync</c> and leave <c>Connecting</c> (that state deliberately fast-fails
+    ///     writes with "driver not connected"), and the host has to push the NodeId→driver reverse map that
+    ///     resolves the write. Telling the write immediately therefore races the setup, which is why this
+    ///     assertion failed roughly 1 run in 30 of the fully parallel assembly — and never once in 60
+    ///     consecutive runs of this class alone.</para>
+    ///     <para><b>Why retrying does not weaken the assertion.</b> Every rejection branch — the Primary
+    ///     gate, an unresolved reverse map, "driver not running", and the child's own pre-Connected
+    ///     fast-fail — replies <em>without</em> reaching the driver. A rejected attempt records nothing, so
+    ///     the caller's <c>Writes.Count.ShouldBe(1)</c> still means exactly what it did before: the accepted
+    ///     write reached the driver exactly once.</para>
+    ///     <para>The failure message carries the last <c>Reason</c> so a genuine regression is diagnosable
+    ///     rather than surfacing as a bare "expected True".</para>
+    /// </remarks>
+    /// <param name="actor">The driver-host actor.</param>
+    /// <param name="nodeId">The ns-qualified NodeId string, as the node manager passes it.</param>
+    /// <param name="value">The value to write.</param>
+    /// <param name="realm">The address-space realm the NodeId belongs to.</param>
+    private void RouteWriteUntilAccepted(
+        IActorRef actor, string nodeId, object value, AddressSpaceRealm realm)
+    {
+        var lastReason = "(no reply)";
+        AwaitAssert(
+            () =>
+            {
+                var asker = CreateTestProbe();
+                actor.Tell(new DriverHostActor.RouteNodeWrite(nodeId, value, realm), asker.Ref);
+                var result = asker.ExpectMsg<DriverHostActor.NodeWriteResult>(TimeSpan.FromSeconds(1));
+                lastReason = result.Reason ?? "(none)";
+                result.Success.ShouldBeTrue($"host kept rejecting the write; last reason: {lastReason}");
+            },
+            duration: Timeout,
+            interval: TimeSpan.FromMilliseconds(50));
+    }
+
     /// <summary>On a SECONDARY, RouteNodeWrite (via the UNS NodeId) replies "not primary" and the driver
     /// receives NO write — the primary gate fires before the reverse-map lookup.</summary>
     [Fact]

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/Drivers/DriverInstanceActorTests.cs

@@ -88,7 +88,7 @@ public sealed class DriverInstanceActorTests : RuntimeActorTestBase
     [Fact]
     public async Task Write_propagates_status_code_on_Bad_result()
     {
-        const uint badStatus = 0x80340000; // BadOutOfService — top severity bits = 10b
+        const uint badStatus = 0x80340000; // BadNodeIdUnknown — top severity bits = 10b
         var driver = new WritableStubDriver { NextStatusCode = badStatus };
         var actor = Sys.ActorOf(DriverInstanceActor.Props(driver));
 

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/Harness/RuntimeActorTestBase.cs

@@ -11,6 +11,25 @@ namespace ZB.MOM.WW.OtOpcUa.Runtime.Tests.Harness;
 /// </summary>
 public abstract class RuntimeActorTestBase : TestKit
 {
+    /// <summary>
+    ///     Shared upper bound for a <b>presence</b> wait (<c>AwaitAssert</c> / <c>AwaitCondition</c>).
+    /// </summary>
+    /// <remarks>
+    ///     <para><b>A budget, not a delay.</b> These helpers poll and return the instant the condition holds,
+    ///     so the value is how long to wait before giving up. Raising it costs nothing on the happy path and
+    ///     <em>cannot</em> make a genuinely failing assertion pass — it only changes how quickly a real
+    ///     breakage is reported. That is the opposite of an <b>absence</b> window (<c>ExpectNoMsg</c>,
+    ///     settle-then-assert), where the elapsed time IS the assertion and every millisecond is spent on
+    ///     every run. Absence windows keep their own short, individually-calibrated literals and must not be
+    ///     routed through here.</para>
+    ///     <para><b>Why it exists (Gitea #500).</b> This assembly runs 44 Akka test classes roughly 14-way
+    ///     parallel, each with its own <see cref="TestKit"/> ActorSystem. Budgets of 300–500 ms sized on an
+    ///     idle machine are comfortable in isolation and marginal under that contention: three consecutive
+    ///     30-run verification rounds each surfaced a <em>different</em> test failing on one, in three
+    ///     different files. Fixing them one at a time was chasing a distribution rather than a defect.</para>
+    /// </remarks>
+    protected static readonly TimeSpan PresenceBudget = TimeSpan.FromSeconds(15);
+
     /// <summary>Gets the Akka test HOCON configuration string for single-node cluster setup.</summary>
     protected static string AkkaTestHocon => @"
 akka {

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/Health/PeerProbeSupervisorTests.cs

@@ -57,7 +57,7 @@ public sealed class PeerProbeSupervisorTests : RuntimeActorTestBase
             State(Adm, RedundancyRole.Detached)));
 
         AwaitAssert(() => sup.UnderlyingActor.ChildCount.ShouldBe(1),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies the child for a departed peer is stopped when the next snapshot omits it.</summary>
@@ -71,11 +71,11 @@ public sealed class PeerProbeSupervisorTests : RuntimeActorTestBase
             State(Local, RedundancyRole.Primary),
             State(Peer, RedundancyRole.Secondary)));
         AwaitAssert(() => sup.UnderlyingActor.ChildCount.ShouldBe(1),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
 
         sup.Tell(Snapshot(State(Local, RedundancyRole.Primary)));
         AwaitAssert(() => sup.UnderlyingActor.ChildCount.ShouldBe(0),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies a single-node snapshot (just the local node) spawns no children.</summary>
@@ -88,7 +88,7 @@ public sealed class PeerProbeSupervisorTests : RuntimeActorTestBase
         sup.Tell(Snapshot(State(Local, RedundancyRole.Primary)));
 
         AwaitAssert(() => sup.UnderlyingActor.ChildCount.ShouldBe(0),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies a previously-removed peer is respawned when it re-appears, without an
@@ -103,17 +103,17 @@ public sealed class PeerProbeSupervisorTests : RuntimeActorTestBase
             State(Local, RedundancyRole.Primary),
             State(Peer, RedundancyRole.Secondary)));
         AwaitAssert(() => sup.UnderlyingActor.ChildCount.ShouldBe(1),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
 
         sup.Tell(Snapshot(State(Local, RedundancyRole.Primary)));
         AwaitAssert(() => sup.UnderlyingActor.ChildCount.ShouldBe(0),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
 
         sup.Tell(Snapshot(
             State(Local, RedundancyRole.Primary),
             State(Peer, RedundancyRole.Secondary)));
         AwaitAssert(() => sup.UnderlyingActor.ChildCount.ShouldBe(1),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Locks in the stale-Terminated guard: when an OLD (already-replaced) child's
@@ -132,27 +132,27 @@ public sealed class PeerProbeSupervisorTests : RuntimeActorTestBase
             State(Local, RedundancyRole.Primary),
             State(Peer, RedundancyRole.Secondary)));
         AwaitAssert(() => sup.UnderlyingActor.ChildCount.ShouldBe(1),
-            duration: TimeSpan.FromMilliseconds(500));
-        AwaitAssert(() => spawned.Count.ShouldBe(1), duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
+        AwaitAssert(() => spawned.Count.ShouldBe(1), duration: PresenceBudget);
         var oldRef = spawned[0];
 
         // Drop the peer -> child #0 stopped, ChildCount back to 0.
         sup.Tell(Snapshot(State(Local, RedundancyRole.Primary)));
         AwaitAssert(() => sup.UnderlyingActor.ChildCount.ShouldBe(0),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
 
         // Re-add the SAME peer -> a NEW child #1 (the FRESH ref) is spawned.
         sup.Tell(Snapshot(
             State(Local, RedundancyRole.Primary),
             State(Peer, RedundancyRole.Secondary)));
         AwaitAssert(() => sup.UnderlyingActor.ChildCount.ShouldBe(1),
-            duration: TimeSpan.FromMilliseconds(500));
-        AwaitAssert(() => spawned.Count.ShouldBe(2), duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
+        AwaitAssert(() => spawned.Count.ShouldBe(2), duration: PresenceBudget);
 
         // Now deliver a STALE Terminated for the OLD ref. The current child for Peer is the fresh
         // child #1, so ref-equality finds no match and the supervisor must leave ChildCount at 1.
         sup.Tell(new Terminated(oldRef, existenceConfirmed: true, addressTerminated: false));
         AwaitAssert(() => sup.UnderlyingActor.ChildCount.ShouldBe(1),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 }

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/Historian/ContinuousHistorizationRecorderTests.cs

@@ -295,10 +295,24 @@ public sealed class ContinuousHistorizationRecorderTests : TestKit
 
         // The first drain returns false (entry retained); after the backoff the retry drain succeeds
         // and acks, truncating the outbox to 0.
-        await AwaitAssertAsync(async () =>
-            Assert.Equal(0, await outbox.CountAsync(default)), TimeSpan.FromSeconds(5));
-
-        Assert.True(writer.CallCount >= 2, "the writer must have been called at least twice (a retry happened)");
+        //
+        // BOTH conditions are polled together, and the retry count is the load-bearing one. An empty
+        // outbox is NOT a distinguishing observation: it is equally true BEFORE the append lands, so
+        // waiting on it alone can be satisfied by the initial state and return before the recorder has
+        // done anything at all. That is exactly what happened intermittently under a fully parallel
+        // assembly run — the poll won the race against the first append, the wait returned immediately,
+        // and the CallCount check that used to sit outside the block then failed against a recorder that
+        // had not yet run. (The same trap is called out on the preceding test, which guards against it by
+        // pairing its count with a writer observation.)
+        await AwaitAssertAsync(
+            async () =>
+            {
+                Assert.True(
+                    writer.CallCount >= 2,
+                    "the writer must have been called at least twice (a retry happened)");
+                Assert.Equal(0, await outbox.CountAsync(default));
+            },
+            TimeSpan.FromSeconds(5));
     }
 
     [Fact]

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/Historian/HistorianAdapterActorTests.cs

@@ -23,9 +23,27 @@ public sealed class HistorianAdapterActorTests : RuntimeActorTestBase
     /// <summary>The local node id the gating tests construct the adapter with.</summary>
     private static readonly NodeId LocalNode = new("node-A");
 
-    /// <summary>A short window we allow the fire-and-forget enqueue to land within.</summary>
+    /// <summary>
+    ///     The window an <b>absence</b> assertion waits before concluding nothing arrived
+    ///     (<c>ExpectNoMsg</c>). Its length is a calibration decision — long enough that a message which
+    ///     was going to arrive would have — so it is deliberately NOT generous.
+    /// </summary>
     private static readonly TimeSpan Settle = TimeSpan.FromMilliseconds(500);
 
+    /// <summary>
+    ///     The budget a <b>presence</b> assertion may take to become true (<c>AwaitAssert</c>).
+    /// </summary>
+    /// <remarks>
+    ///     Separate from <see cref="Settle"/> on purpose, though they once shared its 500 ms. The two are
+    ///     different quantities that merely had the same number: a presence budget is an upper bound before
+    ///     giving up, and <c>AwaitAssert</c> returns the instant the condition holds, so a generous value
+    ///     costs nothing in the passing case and can never make a genuinely failing assertion pass. An
+    ///     absence window is the opposite — every millisecond is spent on every run. Conflating them meant
+    ///     the enqueue assertions could only be given more headroom by slowing every <c>ExpectNoMsg</c> in
+    ///     the class, so they kept a 500 ms budget that a fully parallel assembly run occasionally missed.
+    /// </remarks>
+    private static readonly TimeSpan AssertTimeout = TimeSpan.FromSeconds(5);
+
     /// <summary>Thread-safe fake sink that records every <see cref="EnqueueAsync"/> call.</summary>
     private sealed class RecordingSink : IAlarmHistorianSink
     {
@@ -101,7 +119,7 @@ public sealed class HistorianAdapterActorTests : RuntimeActorTestBase
 
         actor.Tell(SampleEvent());
 
-        AwaitAssert(() => sink.EnqueueCount.ShouldBe(1), Settle);
+        AwaitAssert(() => sink.EnqueueCount.ShouldBe(1), AssertTimeout);
     }
 
     /// <summary>Secondary suppression (T2): when the cached local role is Secondary, the adapter MUST
@@ -145,7 +163,7 @@ public sealed class HistorianAdapterActorTests : RuntimeActorTestBase
         TellRedundancyRole(actor, RedundancyRole.Primary);
         actor.Tell(SampleEvent());
 
-        AwaitAssert(() => sink.EnqueueCount.ShouldBe(1), Settle);
+        AwaitAssert(() => sink.EnqueueCount.ShouldBe(1), AssertTimeout);
     }
 
     /// <summary>Absent-node default-historize (T5): a snapshot that mentions only a DIFFERENT node
@@ -174,7 +192,7 @@ public sealed class HistorianAdapterActorTests : RuntimeActorTestBase
         actor.Tell(SampleEvent());
 
         // Local role is still unknown ⇒ default-historize path: sink must record exactly one enqueue.
-        AwaitAssert(() => sink.EnqueueCount.ShouldBe(1), Settle);
+        AwaitAssert(() => sink.EnqueueCount.ShouldBe(1), AssertTimeout);
     }
 
     /// <summary>Builds an <see cref="AlarmTransitionEvent"/> (the shape published on the <c>alerts</c>
@@ -222,7 +240,7 @@ public sealed class HistorianAdapterActorTests : RuntimeActorTestBase
                 e.Severity.ShouldBe(AlarmSeverity.High);
                 e.Comment.ShouldBe("note");
             },
-            Settle);
+            AssertTimeout);
     }
 
     /// <summary>Secondary suppression for alerts (T7): a Secondary node must NOT historize a transition
@@ -252,7 +270,7 @@ public sealed class HistorianAdapterActorTests : RuntimeActorTestBase
         TellRedundancyRole(actor, RedundancyRole.Primary);
         actor.Tell(SampleTransition());
 
-        AwaitAssert(() => sink.EnqueueCount.ShouldBe(1), Settle);
+        AwaitAssert(() => sink.EnqueueCount.ShouldBe(1), AssertTimeout);
     }
 
     /// <summary>Per-alarm opt-out (T8b): a Primary node must NOT historize a transition whose
@@ -286,7 +304,7 @@ public sealed class HistorianAdapterActorTests : RuntimeActorTestBase
         TellRedundancyRole(actor, RedundancyRole.Primary);
         actor.Tell(SampleTransition(historizeToAveva: null));
 
-        AwaitAssert(() => sink.EnqueueCount.ShouldBe(1), Settle);
+        AwaitAssert(() => sink.EnqueueCount.ShouldBe(1), AssertTimeout);
     }
 
     /// <summary>Severity buckets (T9): the OPC UA 1–1000 numeric severity on the transition maps onto
@@ -308,7 +326,7 @@ public sealed class HistorianAdapterActorTests : RuntimeActorTestBase
 
         AwaitAssert(
             () => sink.Events.ShouldHaveSingleItem().Severity.ShouldBe(expected),
-            Settle);
+            AssertTimeout);
     }
 
     /// <summary>Rolling-restart null default (T10): an old-format transition deserialized by Akka's JSON
@@ -326,6 +344,6 @@ public sealed class HistorianAdapterActorTests : RuntimeActorTestBase
 
         AwaitAssert(
             () => sink.Events.ShouldHaveSingleItem().AlarmTypeName.ShouldBe("AlarmCondition"),
-            Settle);
+            AssertTimeout);
     }
 }

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/OpcUa/OpcUaPublishActorApplyFailureTests.cs

@@ -48,11 +48,16 @@ public sealed class OpcUaPublishActorApplyFailureTests : RuntimeActorTestBase
         var dep2 = SeedEquipmentDeployment(db, ("eq-1", "eq-1-renamed"));
         actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId(), new DeploymentId(dep2)));
 
+        // A PRESENCE budget, so it is an upper bound before giving up rather than a wait: the helper polls
+        // and returns the instant the meter fires, so a generous value costs nothing on the happy path and
+        // can never make a genuinely failing assertion pass. Two seconds covered an idle machine but not a
+        // fully parallel assembly run, where this deploy→rebuild→throw chain (two DB-backed applies) has to
+        // share 14 cores with 40-odd other Akka test classes; it failed there roughly 1 run in 30.
         AwaitAssert(() =>
         {
             recorder.Total.ShouldBeGreaterThanOrEqualTo(1);
             recorder.WithTag("kind", "rebuild").ShouldBeGreaterThanOrEqualTo(1);
-        }, duration: TimeSpan.FromSeconds(2));
+        }, duration: TimeSpan.FromSeconds(15));
     }
 
     /// <summary>A clean rebuild does NOT increment the apply-failed meter (Info-only happy path).</summary>

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/OpcUa/OpcUaPublishActorRebuildTests.cs

@@ -45,7 +45,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
             sink.Calls.ShouldContain("EF:eq-1");
             sink.Calls.ShouldContain("EF:eq-2");
             sink.Calls.ShouldContain("NA:line-1");
-        }, duration: TimeSpan.FromSeconds(2));
+        }, duration: PresenceBudget);
         sink.RebuildCalls.ShouldBe(0);
     }
 
@@ -85,7 +85,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
             sink: sink, dbFactory: db, applier: applier));
 
         actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId()));
-        AwaitAssert(() => sink.Calls.ShouldContain("EF:eq-1"), duration: TimeSpan.FromSeconds(2));
+        AwaitAssert(() => sink.Calls.ShouldContain("EF:eq-1"), duration: PresenceBudget);
         sink.RebuildCalls.ShouldBe(0);          // PureAdd — no full rebuild
         var callsAfterFirst = sink.Calls.Count;
 
@@ -107,7 +107,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
 
         actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId()));
 
-        AwaitAssert(() => sink.RebuildCalls.ShouldBe(1), duration: TimeSpan.FromMilliseconds(500));
+        AwaitAssert(() => sink.RebuildCalls.ShouldBe(1), duration: PresenceBudget);
     }
 
     /// <summary>
@@ -132,7 +132,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
         actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId(), Artifact: artifact));
 
         // The in-hand bytes drove the real diff-and-apply — the equipment folder was materialised…
-        AwaitAssert(() => sink.Calls.ShouldContain("EF:eq-1"), duration: TimeSpan.FromSeconds(2));
+        AwaitAssert(() => sink.Calls.ShouldContain("EF:eq-1"), duration: PresenceBudget);
         // …and the address-space-wiping raw-sink fallback was NOT taken.
         sink.RebuildCalls.ShouldBe(0);
     }
@@ -176,7 +176,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
 
         actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId()));
 
-        AwaitAssert(() => sink.RebuildCalls.ShouldBe(1), duration: TimeSpan.FromMilliseconds(500));
+        AwaitAssert(() => sink.RebuildCalls.ShouldBe(1), duration: PresenceBudget);
     }
 
     /// <summary>
@@ -197,7 +197,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
 
         actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId(), new DeploymentId(dep)));
 
-        AwaitAssert(() => sink.Calls.ShouldContain("EF:eq-1"), duration: TimeSpan.FromSeconds(2));
+        AwaitAssert(() => sink.Calls.ShouldContain("EF:eq-1"), duration: PresenceBudget);
         sink.RebuildCalls.ShouldBe(0);
     }
 
@@ -230,7 +230,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
 
         // PureAdd (equipment + tag) ⇒ no full rebuild; the materialise passes still run the cluster slice.
         // t-sa (EquipmentId "eq-sa", FolderPath "F", Name "S1") → folder-scoped variable "eq-sa/F/S1".
-        AwaitAssert(() => sinkA.Calls.ShouldContain("EV:eq-sa/F/S1"), duration: TimeSpan.FromSeconds(2));
+        AwaitAssert(() => sinkA.Calls.ShouldContain("EV:eq-sa/F/S1"), duration: PresenceBudget);
         sinkA.RebuildCalls.ShouldBe(0);
         // t-main (MAIN cluster) must NOT leak onto the SITE-A node.
         sinkA.Calls.ShouldNotContain("EV:eq-main/F/M1");
@@ -249,7 +249,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
 
         mainActor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId()));
 
-        AwaitAssert(() => sinkM.Calls.ShouldContain("EV:eq-main/F/M1"), duration: TimeSpan.FromSeconds(2));
+        AwaitAssert(() => sinkM.Calls.ShouldContain("EV:eq-main/F/M1"), duration: PresenceBudget);
         sinkM.RebuildCalls.ShouldBe(0);
         sinkM.Calls.ShouldNotContain("EV:eq-sa/F/S1");
     }
@@ -331,7 +331,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
         var actor = Sys.ActorOf(OpcUaPublishActor.PropsForTests(sink: sink, dbFactory: db, applier: applier));
         actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId()));
 
-        AwaitAssert(() => sink.Calls.ShouldContain("NA:line-1"), duration: TimeSpan.FromSeconds(2));
+        AwaitAssert(() => sink.Calls.ShouldContain("NA:line-1"), duration: PresenceBudget);
         sink.RebuildCalls.ShouldBe(0);
 
         var calls = sink.Calls.ToList();
@@ -356,7 +356,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
         var actor = Sys.ActorOf(OpcUaPublishActor.PropsForTests(sink: sink, dbFactory: db, applier: applier));
 
         actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId(), new DeploymentId(dep1)));
-        AwaitAssert(() => sink.Calls.Count(c => c.StartsWith("NA:")).ShouldBe(1), duration: TimeSpan.FromSeconds(2));
+        AwaitAssert(() => sink.Calls.Count(c => c.StartsWith("NA:")).ShouldBe(1), duration: PresenceBudget);
         sink.RebuildCalls.ShouldBe(0);
         var naAfterFirst = sink.Calls.Count(c => c.StartsWith("NA:"));
 
@@ -365,7 +365,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
         var dep2 = SeedNamedEquipmentDeployment(db, ("eq-1", "Pump-1-RENAMED"), ("eq-2", "Pump-2"));
         actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId(), new DeploymentId(dep2)));
 
-        AwaitAssert(() => sink.RebuildCalls.ShouldBe(1), duration: TimeSpan.FromSeconds(2));
+        AwaitAssert(() => sink.RebuildCalls.ShouldBe(1), duration: PresenceBudget);
         // No new NodeAdded announcement was raised for the rebuild-kind deploy.
         sink.Calls.Count(c => c.StartsWith("NA:")).ShouldBe(naAfterFirst);
     }
@@ -388,7 +388,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
 
         var actor = Sys.ActorOf(OpcUaPublishActor.PropsForTests(sink: sink, dbFactory: db, applier: applier));
         actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId(), new DeploymentId(dep1)));
-        AwaitAssert(() => sink.Calls.ShouldContain("EF:eq-2"), duration: TimeSpan.FromSeconds(2));
+        AwaitAssert(() => sink.Calls.ShouldContain("EF:eq-2"), duration: PresenceBudget);
         var callsAfterFirst = sink.Calls.Count;
 
         // The next deploy arrives while the ConfigDb is briefly unreachable.
@@ -423,13 +423,13 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
 
         var actor = Sys.ActorOf(OpcUaPublishActor.PropsForTests(sink: sink, dbFactory: db, applier: applier));
         actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId(), new DeploymentId(dep1)));
-        AwaitAssert(() => sink.Calls.ShouldContain("EF:eq-2"), duration: TimeSpan.FromSeconds(2));
+        AwaitAssert(() => sink.Calls.ShouldContain("EF:eq-2"), duration: PresenceBudget);
 
         // eq-2 really is gone from the next artifact — that IS a configuration change, so it must apply.
         var dep2 = SeedNamedEquipmentDeployment(db, ("eq-1", "Pump-1"));
         actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId(), new DeploymentId(dep2)));
 
-        AwaitAssert(() => sink.Calls.ShouldContain("RE:eq-2"), duration: TimeSpan.FromSeconds(2));
+        AwaitAssert(() => sink.Calls.ShouldContain("RE:eq-2"), duration: PresenceBudget);
     }
 
     /// <summary>An <see cref="IDbContextFactory{TContext}"/> whose <c>CreateDbContext</c> can be made to
@@ -552,7 +552,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
         // First deploy: the area folder is materialised with the OLD name. R2-07 — this is now a PureAdd
         // (area + line + equipment all added), so NO full rebuild; the folder is materialised directly.
         actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId(), new DeploymentId(dep1)));
-        AwaitAssert(() => sink.Calls.ShouldContain("EF:area-1"), duration: TimeSpan.FromSeconds(2));
+        AwaitAssert(() => sink.Calls.ShouldContain("EF:area-1"), duration: PresenceBudget);
         sink.RebuildCalls.ShouldBe(0);
 
         // Second deploy: ONLY the area Name changed — a rename. The actor must reach the apply path and
@@ -563,7 +563,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
         AwaitAssert(() =>
         {
             sink.FolderRenameCalls.ShouldContain(("area-1", "Plant South"));
-        }, duration: TimeSpan.FromSeconds(2));
+        }, duration: PresenceBudget);
         sink.RebuildCalls.ShouldBe(0); // the rename did NOT force a full rebuild
     }
 

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/OpcUa/OpcUaPublishActorTests.cs

@@ -53,7 +53,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             sink.Values[0].Value.ShouldBe(3.14);
             sink.Values[0].Quality.ShouldBe(OpcUaQuality.Good);
             sink.Values[1].Quality.ShouldBe(OpcUaQuality.Uncertain);
-        }, duration: TimeSpan.FromMilliseconds(500));
+        }, duration: PresenceBudget);
     }
 
     /// <summary>Verifies that AlarmStateUpdate routes to sink WriteAlarmCondition with the full snapshot.</summary>
@@ -73,7 +73,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             sink.Alarms[0].State.Active.ShouldBeTrue();
             sink.Alarms[0].State.Acknowledged.ShouldBeFalse();
             sink.Alarms[0].State.Severity.ShouldBe((ushort)700);
-        }, duration: TimeSpan.FromMilliseconds(500));
+        }, duration: PresenceBudget);
     }
 
     /// <summary>#477 — AlarmQualityUpdate routes to sink.WriteAlarmQuality with the quality + realm.</summary>
@@ -93,7 +93,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             q.AlarmNodeId.ShouldBe("Plant/Modbus/dev1/temp_hi");
             q.Quality.ShouldBe(OpcUaQuality.Bad);
             q.Realm.ShouldBe(AddressSpaceRealm.Raw);
-        }, duration: TimeSpan.FromMilliseconds(500));
+        }, duration: PresenceBudget);
     }
 
     /// <summary>Builds a test <see cref="AlarmConditionSnapshot"/> with sensible defaults so each test
@@ -117,7 +117,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
 
         actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId()));
 
-        AwaitAssert(() => sink.RebuildCalls.ShouldBe(1), duration: TimeSpan.FromMilliseconds(500));
+        AwaitAssert(() => sink.RebuildCalls.ShouldBe(1), duration: PresenceBudget);
     }
 
     /// <summary>Verifies that <see cref="OpcUaPublishActor.MaterialiseDiscoveredNodes"/> forwards to the
@@ -146,7 +146,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             sink.Folders.ShouldContain(("EQ-1/Axes", "EQ-1", "Axes"));
             sink.Variables.ShouldContain(("EQ-1/Axes/X", "EQ-1/Axes", "X", "Double", false));
             sink.ModelChanges.ShouldContain("EQ-1");
-        }, duration: TimeSpan.FromMilliseconds(500));
+        }, duration: PresenceBudget);
     }
 
     /// <summary>Verifies that ServiceLevelChanged publishes to IServiceLevelPublisher once per unique level.</summary>
@@ -161,7 +161,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
         actor.Tell(new OpcUaPublishActor.ServiceLevelChanged(100));
 
         AwaitAssert(() => publisher.Levels.ShouldBe(new byte[] { 240, 100 }),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies that the very first computed ServiceLevel is always published even when it is
@@ -186,7 +186,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             CorrelationId.NewId()));
 
         AwaitAssert(() => publisher.Levels.ShouldBe(new byte[] { 0 }),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies that RedundancyStateChanged drives local ServiceLevel publish for primary leader.</summary>
@@ -210,7 +210,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
         actor.Tell(snapshot);
 
         AwaitAssert(() => publisher.Levels.ShouldBe(new byte[] { 240 }),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies that RedundancyStateChanged for secondary publishes 100.</summary>
@@ -231,7 +231,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
         actor.Tell(snapshot);
 
         AwaitAssert(() => publisher.Levels.ShouldBe(new byte[] { 100 }),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies that the calculator path computes 250 for a healthy primary role-leader
@@ -256,7 +256,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             CorrelationId.NewId()));
 
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)250),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies that the calculator path computes 240 for a healthy non-leader secondary
@@ -282,7 +282,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             CorrelationId.NewId()));
 
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)240),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies that the calculator path computes 100 when the DB is unreachable
@@ -307,7 +307,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             CorrelationId.NewId()));
 
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)100),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies that the calculator path computes 200 for a stale snapshot when the DB is
@@ -335,7 +335,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             CorrelationId.NewId()));
 
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)200),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies that a detached local node publishes 0 (the calculator does not model
@@ -362,7 +362,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             },
             CorrelationId.NewId()));
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)250),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
 
         // Now detach — expect the guard to drive ServiceLevel down to 0.
         actor.Tell(new RedundancyStateChanged(
@@ -374,7 +374,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             CorrelationId.NewId()));
 
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)0),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies that an actively-observed, recent peer probe of MY endpoint that came back
@@ -403,7 +403,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             CorrelationId.NewId()));
 
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)0),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies branch (3) of <c>OpcUaProbeOk()</c>: a peer's NEGATIVE verdict about this node
@@ -447,7 +447,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
 
         // Healthy (250), NOT 0 — proves an aged negative verdict does not demote.
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)250),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies that with no peer probe result ever received, <c>OpcUaProbeOk()</c> defaults
@@ -474,7 +474,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             CorrelationId.NewId()));
 
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)250),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies that a later <c>Ok==true</c> peer probe supersedes an earlier <c>Ok==false</c>
@@ -503,7 +503,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             CorrelationId.NewId()));
 
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)240),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies that a peer probe result about a DIFFERENT node is ignored — it does not
@@ -531,7 +531,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             CorrelationId.NewId()));
 
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)250),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies the legacy back-compat seam: with no DB-health probe wired, the handler
@@ -553,7 +553,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             CorrelationId.NewId()));
 
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)240),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Verifies that the periodic <c>HealthTick</c> Asks the local <see cref="DbHealthProbeActor"/>
@@ -607,7 +607,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             CorrelationId.NewId()));
 
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)240),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>DB-less, member Up, snapshot fresh, Primary → 250 (basis 240 + 10 Primary bonus).</summary>
@@ -629,7 +629,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             CorrelationId.NewId()));
 
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)250),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>DB-less, snapshot stale (entry.AsOfUtc older than the stale window) → 200. Staleness
@@ -654,7 +654,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             CorrelationId.NewId()));
 
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)200),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>DB-less, Detached → 0. The Detached / missing-entry guard runs ABOVE the DB-less
@@ -677,7 +677,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             },
             CorrelationId.NewId()));
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)250),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
 
         actor.Tell(new RedundancyStateChanged(
             Nodes: new[]
@@ -688,7 +688,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             CorrelationId.NewId()));
 
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)0),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Regression: a DB-BACKED node (probe wired + DbHealthStatus reachable, dbLess default
@@ -714,7 +714,7 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
             CorrelationId.NewId()));
 
         AwaitAssert(() => publisher.Levels.ShouldContain((byte)240),
-            duration: TimeSpan.FromMilliseconds(500));
+            duration: PresenceBudget);
     }
 
     /// <summary>Stub DB-health probe actor that answers <see cref="DbHealthProbeActor.GetStatus"/>

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/ScriptedAlarms/ScriptedAlarmHostActorTests.cs

@@ -28,7 +28,23 @@ namespace ZB.MOM.WW.OtOpcUa.Runtime.Tests.ScriptedAlarms;
 /// </summary>
 public sealed class ScriptedAlarmHostActorTests : RuntimeActorTestBase
 {
-    private static readonly TimeSpan Timeout = TimeSpan.FromSeconds(8);
+    /// <summary>
+    ///     Upper bound for the <b>presence</b> waits in this class (<c>ExpectMsg</c> / <c>FishForMessage</c>).
+    /// </summary>
+    /// <remarks>
+    ///     <para>Sized for a <b>real Roslyn compilation</b>, not for message passing.
+    ///     <c>ApplyScriptedAlarms</c> drives <c>ScriptedAlarmEngine.LoadAsync</c>, which compiles every
+    ///     alarm predicate through <c>ScriptEvaluator.Compile</c>; the <c>RegisterInterest</c> these tests
+    ///     wait on is only sent once that finishes. A cold C# script compile is slow and highly variable —
+    ///     far more so than anything else in this assembly — and Roslyn's caches are per-process, so the
+    ///     first class to compile pays the worst of it. Under a fully parallel assembly run, sharing 14
+    ///     cores with 40-odd other Akka test classes, 8 s was occasionally missed (Gitea #500).</para>
+    ///     <para>Raising it is free on the happy path: these waits return the instant the message arrives,
+    ///     so the value is an upper bound before giving up, not a delay, and it cannot make a genuinely
+    ///     failing expectation pass. The <b>absence</b> assertions in this class deliberately keep their own
+    ///     short literals — there the elapsed time is the point.</para>
+    /// </remarks>
+    private static readonly TimeSpan Timeout = TimeSpan.FromSeconds(30);
 
     /// <summary>Plan whose predicate compares the single tag "M.T" against 90 — enabled by default.</summary>
     private static EquipmentScriptedAlarmPlan Plan(
@@ -70,20 +86,22 @@ public sealed class ScriptedAlarmHostActorTests : RuntimeActorTestBase
             Retain: false,
             Enabled: true);
 
-    private static ScriptedAlarmEngine BuildEngine(DependencyMuxTagUpstreamSource upstream)
+    private static ScriptedAlarmEngine BuildEngine(
+        DependencyMuxTagUpstreamSource upstream, IAlarmStateStore? store = null)
     {
         var logger = new LoggerConfiguration().CreateLogger();
-        return new ScriptedAlarmEngine(upstream, new InMemoryAlarmStateStore(), new ScriptLoggerFactory(logger), logger);
+        return new ScriptedAlarmEngine(
+            upstream, store ?? new InMemoryAlarmStateStore(), new ScriptLoggerFactory(logger), logger);
     }
 
     /// <summary>The local node id used by the redundancy-gating tests.</summary>
     private static readonly NodeId LocalNode = new("node-A");
 
     private (IActorRef Host, DependencyMuxTagUpstreamSource Upstream) Spawn(
-        TestProbe publish, TestProbe mux, NodeId? localNode = null)
+        TestProbe publish, TestProbe mux, NodeId? localNode = null, IAlarmStateStore? store = null)
     {
         var upstream = new DependencyMuxTagUpstreamSource();
-        var engine = BuildEngine(upstream);
+        var engine = BuildEngine(upstream, store);
         var host = Sys.ActorOf(ScriptedAlarmHostActor.Props(publish.Ref, mux.Ref, upstream, engine, localNode));
         return (host, upstream);
     }
@@ -778,4 +796,162 @@ public sealed class ScriptedAlarmHostActorTests : RuntimeActorTestBase
         evt.AlarmId.ShouldBe("alm-1");
         evt.TransitionKind.ShouldBe("Activated");
     }
+
+    // ---------------------------------------------------------------------------------------------
+    // #487 — post-(re)load condition-node re-assert.
+    //
+    // A deploy that triggers a FULL address-space rebuild re-materialises every condition node fresh
+    // (inactive/acked/confirmed/unshelved). The engine reloads its persisted state and re-derives Active
+    // from the predicate, so it ends up CORRECT — but a still-active alarm has no transition to report,
+    // yielding EmissionKind.None, which OnEngineEmission drops. Without the re-assert the node reads
+    // NORMAL to every OPC UA client until the alarm's next real transition — which, for an alarm with
+    // static dependencies, may never come.
+    // ---------------------------------------------------------------------------------------------
+
+    /// <summary>A persisted condition state as it survives a restart / redeploy, seeded into the store the
+    /// host's engine loads from.</summary>
+    private static AlarmConditionState Persisted(
+        string alarmId = "alm-1",
+        AlarmEnabledState enabled = AlarmEnabledState.Enabled,
+        AlarmActiveState active = AlarmActiveState.Active,
+        AlarmAckedState acked = AlarmAckedState.Unacknowledged,
+        AlarmConfirmedState confirmed = AlarmConfirmedState.Confirmed,
+        ShelvingKind shelving = ShelvingKind.Unshelved,
+        DateTime? lastTransitionUtc = null) =>
+        new(alarmId,
+            enabled,
+            active,
+            acked,
+            confirmed,
+            shelving == ShelvingKind.Unshelved ? ShelvingState.Unshelved : new ShelvingState(shelving, null),
+            lastTransitionUtc ?? DateTime.UtcNow,
+            LastActiveUtc: active == AlarmActiveState.Active ? lastTransitionUtc ?? DateTime.UtcNow : null,
+            LastClearedUtc: null,
+            LastAckUtc: null, LastAckUser: null, LastAckComment: null,
+            LastConfirmUtc: null, LastConfirmUser: null, LastConfirmComment: null,
+            Comments: []);
+
+    /// <summary>Seed <paramref name="state"/> into a fresh store and hand it back for
+    /// <see cref="Spawn"/>. The engine reads it during LoadAsync, exactly as it would after a restart.</summary>
+    private static IAlarmStateStore StoreWith(AlarmConditionState state)
+    {
+        var store = new InMemoryAlarmStateStore();
+        store.SaveAsync(state, CancellationToken.None).GetAwaiter().GetResult();
+        return store;
+    }
+
+    /// <summary>#487, the regression: an alarm whose persisted state is ACTIVE emits nothing on reload
+    /// (no transition to report), but the host must still write its state onto the freshly materialised
+    /// condition node — otherwise an active alarm silently reads normal after a full-rebuild deploy.</summary>
+    [Fact]
+    public void Reload_reasserts_an_active_alarm_onto_its_condition_node()
+    {
+        var publish = CreateTestProbe();
+        var mux = CreateTestProbe();
+        var (host, _) = Spawn(publish, mux, store: StoreWith(Persisted()));
+
+        host.Tell(new ScriptedAlarmHostActor.ApplyScriptedAlarms(new[] { Plan(severity: 800) }));
+
+        var state = publish.ExpectMsg<OpcUaPublishActor.AlarmStateUpdate>(Timeout);
+        state.AlarmNodeId.ShouldBe("alm-1");
+        state.Realm.ShouldBe(AddressSpaceRealm.Uns);
+        state.State.Active.ShouldBeTrue("the persisted state was Active — the rebuilt node must say so");
+        state.State.Acknowledged.ShouldBeFalse();
+        state.State.Enabled.ShouldBeTrue();
+        // The projection carries the definition's severity + resolved message, so a re-asserted node is
+        // indistinguishable from one the alarm's own transition would have written.
+        state.State.Severity.ShouldBe((ushort)1000); // 800 → Critical bucket → 1000
+        state.State.Message.ShouldBe("condition");
+    }
+
+    /// <summary>The re-assert is node-ONLY: it must never reach the <c>alerts</c> topic. That topic is the
+    /// historization path, so an alerts row per alarm per deploy would append a duplicate historian /
+    /// AVEVA record every time anyone deploys.</summary>
+    [Fact]
+    public void Reassert_never_publishes_to_the_alerts_topic()
+    {
+        var publish = CreateTestProbe();
+        var mux = CreateTestProbe();
+        var alerts = CreateTestProbe();
+        SubscribeToAlerts(alerts);
+
+        var (host, _) = Spawn(publish, mux, store: StoreWith(Persisted()));
+        host.Tell(new ScriptedAlarmHostActor.ApplyScriptedAlarms(new[] { Plan() }));
+
+        // Wait for the re-assert to actually happen FIRST — otherwise the absence window below could
+        // elapse before the load even completed and would prove nothing.
+        publish.ExpectMsg<OpcUaPublishActor.AlarmStateUpdate>(Timeout);
+
+        // Absence assertion: the elapsed time IS the assertion, so this stays deliberately short.
+        alerts.ExpectNoMsg(TimeSpan.FromMilliseconds(500));
+    }
+
+    /// <summary>An alarm sitting in the Part 9 no-event position already matches what the materialise
+    /// built, so it is NOT re-asserted — a deploy where nothing is in alarm writes no condition nodes at
+    /// all, and a never-fired alarm keeps the display name the materialise seeded as its Message.</summary>
+    [Fact]
+    public void A_normal_alarm_is_not_reasserted()
+    {
+        var publish = CreateTestProbe();
+        var mux = CreateTestProbe();
+        var (host, _) = Spawn(publish, mux); // empty store ⇒ Fresh ⇒ no-event position
+
+        host.Tell(new ScriptedAlarmHostActor.ApplyScriptedAlarms(new[] { Plan() }));
+
+        // Sequence the absence: the re-assert (if any) happens right after the mux registration, so
+        // waiting for that first makes the window below cover the moment the write would have landed.
+        mux.ExpectMsg<DependencyMuxActor.RegisterInterest>(Timeout);
+        publish.ExpectNoMsg(TimeSpan.FromMilliseconds(500));
+    }
+
+    /// <summary>Not just Active: every field a rebuild would silently lose is restored. A shelved (but
+    /// inactive) alarm is re-asserted too — a rebuilt node would otherwise come back unshelved, so an
+    /// operator's suppression would evaporate on the next deploy.</summary>
+    [Fact]
+    public void Reload_reasserts_a_shelved_but_inactive_alarm()
+    {
+        var publish = CreateTestProbe();
+        var mux = CreateTestProbe();
+        var (host, _) = Spawn(publish, mux, store: StoreWith(Persisted(
+            active: AlarmActiveState.Inactive,
+            acked: AlarmAckedState.Acknowledged,
+            shelving: ShelvingKind.OneShot)));
+
+        host.Tell(new ScriptedAlarmHostActor.ApplyScriptedAlarms(new[] { Plan() }));
+
+        var state = publish.ExpectMsg<OpcUaPublishActor.AlarmStateUpdate>(Timeout);
+        state.State.Active.ShouldBeFalse();
+        state.State.Shelving.ShouldBe(AlarmShelvingKind.OneShot);
+    }
+
+    /// <summary>The re-asserted timestamp is when the state actually came about, NOT the deploy instant —
+    /// a client reading Time/ReceiveTime after a rebuild should still see when the alarm went active.</summary>
+    [Fact]
+    public void Reassert_carries_the_conditions_own_transition_timestamp()
+    {
+        var publish = CreateTestProbe();
+        var mux = CreateTestProbe();
+        var wentActiveAt = DateTime.UtcNow.AddHours(-3);
+        var (host, _) = Spawn(publish, mux, store: StoreWith(Persisted(lastTransitionUtc: wentActiveAt)));
+
+        host.Tell(new ScriptedAlarmHostActor.ApplyScriptedAlarms(new[] { Plan() }));
+
+        publish.ExpectMsg<OpcUaPublishActor.AlarmStateUpdate>(Timeout)
+            .TimestampUtc.ShouldBe(wentActiveAt);
+    }
+
+    /// <summary>A disabled PLAN exposes no condition node at all (MaterialiseScriptedAlarms skips it) and
+    /// is not loaded into the engine — so it must not be re-asserted either, or the write would target a
+    /// node that does not exist.</summary>
+    [Fact]
+    public void A_disabled_plan_is_not_reasserted()
+    {
+        var publish = CreateTestProbe();
+        var mux = CreateTestProbe();
+        var (host, _) = Spawn(publish, mux, store: StoreWith(Persisted()));
+
+        host.Tell(new ScriptedAlarmHostActor.ApplyScriptedAlarms(new[] { Plan(enabled: false) }));
+
+        publish.ExpectNoMsg(TimeSpan.FromMilliseconds(500));
+    }
 }

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/VirtualTags/VirtualTagActorTests.cs

@@ -79,7 +79,7 @@ public sealed class VirtualTagActorTests : RuntimeActorTestBase
             entry.Message.ShouldContain("syntax error");
             entry.ScriptId.ShouldBe("script-7");
             entry.VirtualTagId.ShouldBe("vt-1");
-        }, duration: TimeSpan.FromMilliseconds(500));
+        }, duration: PresenceBudget);
 
         // 02/S13: the failure now ALSO degrades the node — with no declared dependencyRefs the
         // inputs-ready gate is vacuously satisfied, so a Bad EvaluationResult reaches the parent (this

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/VirtualTags/VirtualTagHostActorTests.cs

@@ -260,7 +260,15 @@ public sealed class VirtualTagHostActorTests : RuntimeActorTestBase
         // The old child is stopped (PostStop ⇒ UnregisterInterest) and a new one spawned
         // (PreStart ⇒ RegisterInterest on "B"). Both messages arrive at the mux probe; order between
         // the dying child's PostStop and the new child's PreStart is not guaranteed, so accept either.
+        //
+        // Because the order is genuinely undefined, the SENDER of the RegisterInterest must be captured
+        // as that message is received. Reading mux.LastSender after the loop instead would read the
+        // sender of whichever message happened to arrive SECOND — the dying child when the interleaving
+        // is [Register, Unregister] — so the identity assertion below silently depended on the very
+        // ordering this loop exists to tolerate. That made it fail roughly 10% of the time under a
+        // fully parallel assembly run, and never in isolation.
         DependencyMuxActor.RegisterInterest? reg2 = null;
+        IActorRef? secondChild = null;
         var sawUnregister = false;
         for (var i = 0; i < 2; i++)
         {
@@ -269,6 +277,7 @@ public sealed class VirtualTagHostActorTests : RuntimeActorTestBase
             {
                 case DependencyMuxActor.RegisterInterest r:
                     reg2 = r;
+                    secondChild = mux.LastSender;   // sender OF THIS message, not of the last one seen
                     break;
                 case DependencyMuxActor.UnregisterInterest:
                     sawUnregister = true;
@@ -282,7 +291,8 @@ public sealed class VirtualTagHostActorTests : RuntimeActorTestBase
         reg2.TagRefs.ShouldNotContain("A");
 
         // The replacement is a different actor ref than the original (auto-named, so no collision).
-        mux.LastSender.ShouldNotBe(firstChild);
+        secondChild.ShouldNotBeNull();
+        secondChild.ShouldNotBe(firstChild);
     }
 
     /// <summary>