feat(audit): ScriptTrace channel + RouteCall/ScriptRun/AttributeWrite/AttributeWait kinds

Flow Debugger (design 2026-09-05 §5.1): trace steps are audit rows. New
AuditChannel.ScriptTrace appended after Cluster and four kinds appended after
ManualFailover so stored ordinals never move; lock-in tests + alog.md §4 updated.

Claude-Session: https://claude.ai/code/session_01GSLkkHKz9JrAtmJjmQK3cP

alog.md

@@ -135,7 +135,7 @@ Single wide table, polymorphic by `Channel` + `Kind` discriminators, JSON payloa
 - `IX_AuditLog_Target_Occurred (Target, OccurredAtUtc)` — "what did we send to system X."
 - Partitioning by month on `OccurredAtUtc` from day one (purge becomes a partition switch instead of a delete storm).
 
-**`Kind` values (flat — 17 discriminators across all channels; pinned by `AuditEnumTests`):**
+**`Kind` values (flat — 21 discriminators across all channels; pinned by `AuditEnumTests`):**
 
 | Kind | Fires when |
 |---|---|
@@ -156,6 +156,10 @@ Single wide table, polymorphic by `Channel` + `Kind` discriminators, JSON payloa
 | `SecuredWriteExpire` | A `Pending` secured write aged past its server-side TTL and was transitioned to `Expired` without executing — emitted by the system (no verifier). |
 | `ReconciliationAbandoned` | A reconciliation pull row failed to insert up to the permanent-abandon threshold and central advanced its cursor past it; one synthetic row so the loss is queryable in the Audit Log itself. |
 | `ManualFailover` | An administrator triggered a manual failover of the central pair from the Health page; one row per invocation, written BEFORE the graceful `Cluster.Leave` is issued. `Target` = the leaving node's address. |
+| `RouteCall` | Central `Route.To(...).Call(...)` round-trip completed (success or failure). **Always-on** — one row per routed call regardless of tracing; `Extra.childExecutionId` = the site run's `ExecutionId`. Channel `ScriptTrace`. (Flow Debugger, 2026-09-05) |
+| `ScriptRun` | A traced site script run completed/failed/timed out; `Extra.trigger*` carries the trigger for value-change runs. Channel `ScriptTrace`, traced executions only. |
+| `AttributeWrite` | A traced script wrote an attribute (or a batch); `Extra.writes[]` lists each write's outcome. Channel `ScriptTrace`, traced executions only. |
+| `AttributeWait` | A traced script's `WaitAsync`/`WaitForAsync` resolved (satisfied / timeout / cancelled / error) with the observed value. Channel `ScriptTrace`, traced executions only. |
 
 ### Site: `AuditLog` (SQLite)
 

src/ZB.MOM.WW.ScadaBridge.Commons/Types/Enums/AuditChannel.cs

@@ -21,5 +21,13 @@ public enum AuditChannel
     /// restarted the active node, which is exactly the kind of act an audit log exists to
     /// attribute. (decision 2026-07-22)
     /// </summary>
-    Cluster
+    Cluster,
+
+    /// <summary>
+    /// Flow Debugger trace rows (design 2026-09-05): a script run, an attribute write, an
+    /// attribute wait or a central route call, emitted only for traced executions
+    /// (plus the always-on <see cref="AuditKind.RouteCall"/>). Appended last so stored
+    /// ordinals of existing channels never move.
+    /// </summary>
+    ScriptTrace
 }

src/ZB.MOM.WW.ScadaBridge.Commons/Types/Enums/AuditKind.cs

@@ -49,5 +49,17 @@ public enum AuditKind
     /// is issued (the acting node is usually not the one that goes away, but the audit must
     /// survive either outcome). (decision 2026-07-22)
     /// </summary>
-    ManualFailover
+    ManualFailover,
+
+    /// <summary>Central <c>Route.To().Call</c> round-trip (always-on; <see cref="AuditChannel.ScriptTrace"/> channel).</summary>
+    RouteCall,
+
+    /// <summary>One site script run completed/failed/timed out (traced executions only; <see cref="AuditChannel.ScriptTrace"/>).</summary>
+    ScriptRun,
+
+    /// <summary>One attribute write or batch write made by a traced script (traced executions only; <see cref="AuditChannel.ScriptTrace"/>).</summary>
+    AttributeWrite,
+
+    /// <summary>One <c>WaitAsync</c>/<c>WaitForAsync</c> outcome in a traced script (traced executions only; <see cref="AuditChannel.ScriptTrace"/>).</summary>
+    AttributeWait
 }

tests/ZB.MOM.WW.ScadaBridge.Commons.Tests/Audit/ScriptTraceEnumTests.cs

@@ -0,0 +1,31 @@
+using ZB.MOM.WW.ScadaBridge.Commons.Types.Audit;
+using ZB.MOM.WW.ScadaBridge.Commons.Types.Enums;
+
+namespace ZB.MOM.WW.ScadaBridge.Commons.Tests.Audit;
+
+/// <summary>
+/// Flow Debugger (design 2026-09-05): the <c>ScriptTrace</c> channel and its four kinds must
+/// fit the central <c>AuditLog.Category</c>/<c>Kind</c> columns and never move existing ordinals.
+/// </summary>
+public class ScriptTraceEnumTests
+{
+    [Theory]
+    [InlineData(AuditKind.RouteCall)]
+    [InlineData(AuditKind.ScriptRun)]
+    [InlineData(AuditKind.AttributeWrite)]
+    [InlineData(AuditKind.AttributeWait)]
+    public void ScriptTraceKinds_FitTheCentralColumns(AuditKind kind)
+    {
+        // AuditLog.Category / Kind are nvarchar(32) (AuditLogEntityTypeConfiguration).
+        Assert.True(kind.ToString().Length <= 32);
+        Assert.True(AuditChannel.ScriptTrace.ToString().Length <= 32);
+        Assert.Equal($"ScriptTrace.{kind}", AuditFieldBuilders.BuildAction(AuditChannel.ScriptTrace, kind));
+    }
+
+    [Fact]
+    public void ScriptTrace_IsAppendedAfterCluster_SoExistingOrdinalsAreStable()
+    {
+        Assert.True((int)AuditChannel.ScriptTrace > (int)AuditChannel.Cluster);
+        Assert.True((int)AuditKind.RouteCall > (int)AuditKind.ManualFailover);
+    }
+}

tests/ZB.MOM.WW.ScadaBridge.Commons.Tests/Types/Enums/AuditEnumTests.cs

@@ -12,7 +12,7 @@ public class AuditEnumTests
     [Fact]
     public void AuditChannel_HasExactlyExpectedMembers()
     {
-        var expected = new[] { "ApiOutbound", "DbOutbound", "Notification", "ApiInbound", "SecuredWrite", "Cluster" };
+        var expected = new[] { "ApiOutbound", "DbOutbound", "Notification", "ApiInbound", "SecuredWrite", "Cluster", "ScriptTrace" };
         var actual = Enum.GetValues(typeof(AuditChannel))
             .Cast<AuditChannel>()
             .Select(x => x.ToString())
@@ -23,7 +23,7 @@ public class AuditEnumTests
     }
 
     [Fact]
-    public void AuditKind_HasExactlySeventeenExpectedMembers()
+    public void AuditKind_HasExactlyTwentyOneExpectedMembers()
     {
         var expected = new[]
         {
@@ -34,13 +34,14 @@ public class AuditEnumTests
             "SecuredWriteExpire",
             "ReconciliationAbandoned",
             "ManualFailover",
+            "RouteCall", "ScriptRun", "AttributeWrite", "AttributeWait",
         };
         var actual = Enum.GetValues(typeof(AuditKind))
             .Cast<AuditKind>()
             .Select(x => x.ToString())
             .ToArray();
 
-        Assert.Equal(17, actual.Length);
+        Assert.Equal(21, actual.Length);
         Assert.Equal(expected, actual);
     }