Files
CompiledScriptCache<TContext, TResult> — source-hash-keyed cache of compiled evaluators. Roslyn compilation is the most expensive step in the evaluator pipeline (5-20ms per script depending on size); re-compiling on every value-change event would starve the engine. ConcurrentDictionary of Lazy<ScriptEvaluator> with ExecutionAndPublication mode ensures concurrent callers never double-compile even on a cold cache race. Failed compiles evict the cache entry so an Admin UI retry with corrected source actually recompiles (otherwise the cached exception would persist). Whitespace-sensitive hash — reformatting a script misses the cache on purpose, simpler than AST-canonicalize and happens rarely. No capacity bound because virtual-tag + alarm scripts are config-DB bounded (thousands, not millions); if scale pushes past that in v3 an LRU eviction slots in behind the same API. TimedScriptEvaluator<TContext, TResult> — wraps a ScriptEvaluator with a per-evaluation wall-clock timeout (default 250ms per Phase 7 plan Stream A.4, configurable per tag so slower backends can widen). Critical implementation detail: the underlying Roslyn ScriptRunner executes synchronously on the calling thread for CPU-bound user scripts, returning an already-completed Task before the caller can register a timeout. Naive `Task.WaitAsync(timeout)` would see the completed task and never fire. Fix: push evaluation to a thread-pool thread via Task.Run, so the caller's thread is free to wait and the timeout reliably fires after the configured budget. Known trade-off (documented in the class summary): when a script times out, the underlying evaluation task continues running on the thread-pool thread until Roslyn returns; in the CPU-bound-infinite-loop case it's effectively leaked until the runtime decides to unwind. Tighter CPU budgeting would require an out-of-process script runner (v3 concern). In practice the timeout + structured warning log surfaces the offending script so the operator fixes it, and the orphan thread is rare. Caller-supplied CancellationToken is honored and takes precedence over the timeout, so driver-shutdown paths see a clean OperationCanceledException rather than a misclassified ScriptTimeoutException. ScriptTimeoutException carries the configured Timeout and a diagnostic message pointing the operator at ctx.Logger output around the failure plus suggesting widening the timeout, simplifying the script, or moving heavy work out of the evaluation path. The virtual-tag engine (Stream B) will catch this and map the owning tag's quality to BadInternalError per Phase 7 decision #11, logging a structured warning with the offending script name. Tests: CompiledScriptCacheTests (10) — first-call compile, identical-source dedupe to same instance, different-source produces different evaluator, whitespace-sensitivity documented, cached evaluator still runs correctly, failed compile evicted for retry, Clear drops entries, concurrent GetOrCompile of the same source deduplicates to one instance, different TContext/TResult use separate cache instances, null source rejected. TimedScriptEvaluatorTests (9) — fast script completes under timeout, CPU-bound script throws ScriptTimeoutException, caller cancellation takes precedence over timeout (shutdown path correctness), default 250ms per plan, zero/negative timeout rejected at construction, null inner rejected, null context rejected, user-thrown exceptions propagate unwrapped (not conflated with timeout), timeout exception message contains diagnostic guidance. Full suite: 48/48 green (29 from A.1 + 19 new). Next: Stream A.3 wires the dedicated scripts-*.log Serilog rolling sink + structured-property filtering + companion-WARN enricher to the main log, closing out Stream A. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
AclsTab Probe-this-permission — first of three #196 slices. New /clusters/{ClusterId}/draft/{GenerationId} ACLs-tab gains a probe card above the grant table so operators can ask the trie "if cn=X asks for permission Y on node Z, would it be granted, and which rows contributed?" without shell-ing into the DB. Service thinly wraps the same PermissionTrieBuilder + PermissionTrie.CollectMatches call path the Server's dispatch layer uses at request time, so a probe answer is by construction identical to what the live server would decide. New PermissionProbeService.ProbeAsync(generationId, ldapGroup, NodeScope, requiredFlags) — loads the target generation's NodeAcl rows filtered to the cluster (critical: without the cluster filter, cross-cluster grants leak into the probe which tested false-positive in the unit suite), builds a trie, CollectMatches against the supplied scope + [ldapGroup], ORs the matched-grant flags into Effective, compares to Required. Returns PermissionProbeResult(Granted, Required, Effective, Matches) — Matches carries LdapGroup + Scope + PermissionFlags per matched row so the UI can render the contribution chain. Zero side effects + no audit rows — a failing probe is a question, not a denial. AclsTab.razor gains the probe card at the top (before the New-grant form + grant table): six inputs for ldap group + every NodeScope level (NamespaceId → UnsAreaId → UnsLineId → EquipmentId → TagId — blank fields become null so the trie walks only as deep as the operator specified), a NodePermissions dropdown filtered to skip None, Probe button, green Granted / red Denied badge + Required/Effective bitmask display, and (when matches exist) a small table showing which LdapGroup matched at which level with which flags. Admin csproj adds ProjectReference to Core — the trie + NodeScope live there + were previously Server-only. Five new PermissionProbeServiceTests covering: cluster-level row grants a namespace-level read; no-group-match denies with empty Effective; matching group but insufficient flags (Browse+Read vs WriteOperate required) denies with correct Effective bitmask; cross-cluster grants stay isolated (c2's WriteOperate does NOT leak into c1's probe); generation isolation (gen1's Read-only does NOT let gen2's WriteOperate-requiring probe pass). Admin.Tests 92/92 passing (was 87, +5). Admin builds 0 errors. Remaining #196 slices — SignalR invalidation + draft-diff ACL section — ship in follow-up PRs so the review surface per PR stays tight.
Roslyn analyzer — detect unwrapped driver-capability calls (OTOPCUA0001). Closes task #200. New netstandard2.0 analyzer project src/ZB.MOM.WW.OtOpcUa.Analyzers registered as an <Analyzer>-item ProjectReference from the Server csproj so the warning fires at every Server compile. First (and only so far) rule OTOPCUA0001 — "Driver capability call must be wrapped in CapabilityInvoker" — walks every InvocationOperation in the AST + trips when (a) the target method implements one of the seven guarded capability interfaces (IReadable / IWritable / ITagDiscovery / ISubscribable / IHostConnectivityProbe / IAlarmSource / IHistoryProvider) AND (b) the method's return type is Task, Task<T>, ValueTask, or ValueTask<T> — the async-wire-call constraint narrows the rule to the surfaces the Phase 6.1 pipeline actually wraps + sidesteps pure in-memory accessors like IHostConnectivityProbe.GetHostStatuses() which would trigger false positives AND (c) the call does NOT sit inside a lambda argument passed to CapabilityInvoker.ExecuteAsync / ExecuteWriteAsync / AlarmSurfaceInvoker.*. The wrapper detection walks up the syntax tree from the call site, finds any enclosing InvocationExpressionSyntax whose method's containing type is one of the wrapper classes, + verifies the call lives transitively inside that invocation's AnonymousFunctionExpressionSyntax argument — a sibling "result = await driver.ReadAsync(...)" followed by a separate invoker.ExecuteAsync(...) call does NOT satisfy the wrapping rule + the analyzer flags it (regression guard in the 5th test). Five xunit-v3 + Shouldly tests at tests/ZB.MOM.WW.OtOpcUa.Analyzers.Tests: direct ReadAsync in server namespace trips; wrapped ReadAsync inside CapabilityInvoker.ExecuteAsync lambda passes; direct WriteAsync trips; direct DiscoverAsync trips; sneaky pattern — read outside the lambda + ExecuteAsync with unrelated lambda nearby — still trips. Hand-rolled test harness compiles a stub-plus-user snippet via CSharpCompilation.WithAnalyzers + runs GetAnalyzerDiagnosticsAsync directly, deliberately avoiding Microsoft.CodeAnalysis.CSharp.Analyzer.Testing.XUnit because that package pins to xunit v2 + this repo is on xunit.v3 everywhere else. RS2008 release-tracking noise suppressed by adding AnalyzerReleases.Shipped.md + AnalyzerReleases.Unshipped.md as AdditionalFiles, which is the canonical Roslyn-analyzer hygiene path. Analyzer DLL referenced from Server.csproj via ProjectReference with OutputItemType=Analyzer + ReferenceOutputAssembly=false — the DLL ships as a compiler plugin, not a runtime dependency. Server build validates clean: the analyzer activates on every Server file but finds zero violations, which confirms the Phase 6.1 wrapping work done in prior PRs is complete + the analyzer is now the regression guard preventing the next new capability surface from being added raw. slnx updated with both the src + tests project entries. Full solution build clean, analyzer suite 5/5 passing.
Client rename residuals: lmxopcua-cli → otopcua-cli + LmxOpcUaClient → OtOpcUaClient with migration shim. Closes task #208 (the executable-name + LocalAppData-folder slice that was called out in Client.CLI.md / Client.UI.md as a deliberately-deferred residual of the Phase 0 rename). Six source references flipped to the canonical OtOpcUaClient spelling: Program.cs CliFx executable name + description (lmxopcua-cli → otopcua-cli), DefaultApplicationConfigurationFactory.cs ApplicationName + ApplicationUri (LmxOpcUaClient + urn:localhost:LmxOpcUaClient → OtOpcUaClient + urn:localhost:OtOpcUaClient), OpcUaClientService.CreateSessionAsync session-name arg, ConnectionSettings.CertificateStorePath default, MainWindowViewModel.CertificateStorePath default, JsonSettingsService.SettingsDir. Two consuming tests (ConnectionSettingsTests + MainWindowViewModelTests) updated to assert the new canonical name. New ClientStoragePaths static helper at src/ZB.MOM.WW.OtOpcUa.Client.Shared/ClientStoragePaths.cs is the migration shim — single entry point for the PKI root + pki subpath, runs a one-shot legacy-folder probe on first resolution: if {LocalAppData}/LmxOpcUaClient/ exists + {LocalAppData}/OtOpcUaClient/ does not, Directory.Move renames it in place (atomic on NTFS within the same volume) so trusted server certs + saved connection settings persist across the rename without operator action. Idempotent per-process via a Lock-guarded _migrationChecked flag so repeated CertificateStorePath getter calls on the hot path pay no IO cost beyond the first. Fresh-install path (neither folder exists) + already-migrated path (only canonical exists) + manual-override path (both exist — developer has set up something explicit) are all no-ops that leave state alone. IOException on the Directory.Move is swallowed + logged as a false return so a concurrent peer process losing the race doesn't crash the consumer; the losing process falls back to whatever state exists. Five new ClientStoragePathsTests assert: GetRoot ends with canonical name under LocalAppData, GetPkiPath nests pki under root, CanonicalFolderName is OtOpcUaClient, LegacyFolderName is LmxOpcUaClient (the migration contract — a typo here would leak the legacy folder past the shim), repeat invocation returns false after first-touch arms the in-process guard. Doc-side residual-explanation notes in docs/Client.CLI.md + docs/Client.UI.md are dropped now that the rename is real; replaced with a short "pre-#208 dev boxes migrate automatically on first launch" note that points at ClientStoragePaths. Sample CLI invocations in Client.CLI.md updated via sed from lmxopcua-cli to otopcua-cli across every command block (14 replacements). Pre-existing staleness in SubscribeCommandTests.Execute_PrintsSubscriptionMessage surfaced during the test run — the CLI's subscribe command has long since switched to an aggregate "Subscribed to {count}/{total} nodes (interval: ...)" output format but the test still asserted the original single-node form. Updated the assertion to match current output + added a comment explaining the change; this is unrelated to the rename but was blocking a green Client.CLI.Tests run. Full solution build 0 errors; Client.Shared.Tests 136/136 + 5 new shim tests passing; Client.UI.Tests 98/98; Client.CLI.Tests 52/52 (was 51/52 before the subscribe-test fix). No Admin/Core/Server changes — this touches only the client layer.
Client rename residuals: lmxopcua-cli → otopcua-cli + LmxOpcUaClient → OtOpcUaClient with migration shim. Closes task #208 (the executable-name + LocalAppData-folder slice that was called out in Client.CLI.md / Client.UI.md as a deliberately-deferred residual of the Phase 0 rename). Six source references flipped to the canonical OtOpcUaClient spelling: Program.cs CliFx executable name + description (lmxopcua-cli → otopcua-cli), DefaultApplicationConfigurationFactory.cs ApplicationName + ApplicationUri (LmxOpcUaClient + urn:localhost:LmxOpcUaClient → OtOpcUaClient + urn:localhost:OtOpcUaClient), OpcUaClientService.CreateSessionAsync session-name arg, ConnectionSettings.CertificateStorePath default, MainWindowViewModel.CertificateStorePath default, JsonSettingsService.SettingsDir. Two consuming tests (ConnectionSettingsTests + MainWindowViewModelTests) updated to assert the new canonical name. New ClientStoragePaths static helper at src/ZB.MOM.WW.OtOpcUa.Client.Shared/ClientStoragePaths.cs is the migration shim — single entry point for the PKI root + pki subpath, runs a one-shot legacy-folder probe on first resolution: if {LocalAppData}/LmxOpcUaClient/ exists + {LocalAppData}/OtOpcUaClient/ does not, Directory.Move renames it in place (atomic on NTFS within the same volume) so trusted server certs + saved connection settings persist across the rename without operator action. Idempotent per-process via a Lock-guarded _migrationChecked flag so repeated CertificateStorePath getter calls on the hot path pay no IO cost beyond the first. Fresh-install path (neither folder exists) + already-migrated path (only canonical exists) + manual-override path (both exist — developer has set up something explicit) are all no-ops that leave state alone. IOException on the Directory.Move is swallowed + logged as a false return so a concurrent peer process losing the race doesn't crash the consumer; the losing process falls back to whatever state exists. Five new ClientStoragePathsTests assert: GetRoot ends with canonical name under LocalAppData, GetPkiPath nests pki under root, CanonicalFolderName is OtOpcUaClient, LegacyFolderName is LmxOpcUaClient (the migration contract — a typo here would leak the legacy folder past the shim), repeat invocation returns false after first-touch arms the in-process guard. Doc-side residual-explanation notes in docs/Client.CLI.md + docs/Client.UI.md are dropped now that the rename is real; replaced with a short "pre-#208 dev boxes migrate automatically on first launch" note that points at ClientStoragePaths. Sample CLI invocations in Client.CLI.md updated via sed from lmxopcua-cli to otopcua-cli across every command block (14 replacements). Pre-existing staleness in SubscribeCommandTests.Execute_PrintsSubscriptionMessage surfaced during the test run — the CLI's subscribe command has long since switched to an aggregate "Subscribed to {count}/{total} nodes (interval: ...)" output format but the test still asserted the original single-node form. Updated the assertion to match current output + added a comment explaining the change; this is unrelated to the rename but was blocking a green Client.CLI.Tests run. Full solution build 0 errors; Client.Shared.Tests 136/136 + 5 new shim tests passing; Client.UI.Tests 98/98; Client.CLI.Tests 52/52 (was 51/52 before the subscribe-test fix). No Admin/Core/Server changes — this touches only the client layer.
Client rename residuals: lmxopcua-cli → otopcua-cli + LmxOpcUaClient → OtOpcUaClient with migration shim. Closes task #208 (the executable-name + LocalAppData-folder slice that was called out in Client.CLI.md / Client.UI.md as a deliberately-deferred residual of the Phase 0 rename). Six source references flipped to the canonical OtOpcUaClient spelling: Program.cs CliFx executable name + description (lmxopcua-cli → otopcua-cli), DefaultApplicationConfigurationFactory.cs ApplicationName + ApplicationUri (LmxOpcUaClient + urn:localhost:LmxOpcUaClient → OtOpcUaClient + urn:localhost:OtOpcUaClient), OpcUaClientService.CreateSessionAsync session-name arg, ConnectionSettings.CertificateStorePath default, MainWindowViewModel.CertificateStorePath default, JsonSettingsService.SettingsDir. Two consuming tests (ConnectionSettingsTests + MainWindowViewModelTests) updated to assert the new canonical name. New ClientStoragePaths static helper at src/ZB.MOM.WW.OtOpcUa.Client.Shared/ClientStoragePaths.cs is the migration shim — single entry point for the PKI root + pki subpath, runs a one-shot legacy-folder probe on first resolution: if {LocalAppData}/LmxOpcUaClient/ exists + {LocalAppData}/OtOpcUaClient/ does not, Directory.Move renames it in place (atomic on NTFS within the same volume) so trusted server certs + saved connection settings persist across the rename without operator action. Idempotent per-process via a Lock-guarded _migrationChecked flag so repeated CertificateStorePath getter calls on the hot path pay no IO cost beyond the first. Fresh-install path (neither folder exists) + already-migrated path (only canonical exists) + manual-override path (both exist — developer has set up something explicit) are all no-ops that leave state alone. IOException on the Directory.Move is swallowed + logged as a false return so a concurrent peer process losing the race doesn't crash the consumer; the losing process falls back to whatever state exists. Five new ClientStoragePathsTests assert: GetRoot ends with canonical name under LocalAppData, GetPkiPath nests pki under root, CanonicalFolderName is OtOpcUaClient, LegacyFolderName is LmxOpcUaClient (the migration contract — a typo here would leak the legacy folder past the shim), repeat invocation returns false after first-touch arms the in-process guard. Doc-side residual-explanation notes in docs/Client.CLI.md + docs/Client.UI.md are dropped now that the rename is real; replaced with a short "pre-#208 dev boxes migrate automatically on first launch" note that points at ClientStoragePaths. Sample CLI invocations in Client.CLI.md updated via sed from lmxopcua-cli to otopcua-cli across every command block (14 replacements). Pre-existing staleness in SubscribeCommandTests.Execute_PrintsSubscriptionMessage surfaced during the test run — the CLI's subscribe command has long since switched to an aggregate "Subscribed to {count}/{total} nodes (interval: ...)" output format but the test still asserted the original single-node form. Updated the assertion to match current output + added a comment explaining the change; this is unrelated to the rename but was blocking a green Client.CLI.Tests run. Full solution build 0 errors; Client.Shared.Tests 136/136 + 5 new shim tests passing; Client.UI.Tests 98/98; Client.CLI.Tests 52/52 (was 51/52 before the subscribe-test fix). No Admin/Core/Server changes — this touches only the client layer.
EquipmentNodeWalker — pure-function UNS tree materialization (ADR-001 Task A, task #210). The walker traverses the Config-DB snapshot for a single Equipment-kind namespace (Areas / Lines / Equipment / Tags) and streams IAddressSpaceBuilder.Folder + Variable + AddProperty calls to materialize the canonical 5-level Unified Namespace browse tree that decisions #116-#121 promise external consumers. Pure function: no OPC UA SDK dependency, no DB access, no state — consumes pre-loaded EF Core row collections + streams into the supplied builder. Server-side wiring (load snapshot → call walker → per-tag capability probe) is Task B's scope, alongside NodeScopeResolver's Config-DB join + the ACL integration test that closes task #195. This PR is the Core.OpcUa primitive the server will consume. Walk algorithm — content is grouped up-front (lines by area, equipment by line, tags by equipment) into OrdinalIgnoreCase dictionaries so the per-level nested foreach stays O(N+M) rather than O(N·M) at each UNS level; orderings are deterministic on Name with StringComparer.Ordinal so diffs across runs (e.g. integration-test assertions) are stable. Areas → Lines → Equipment emitted as Folder nodes with browse-name = Name per decision #120. Under each Equipment folder: five identifier properties per decision #121 (EquipmentId + EquipmentUuid always; MachineCode always — it's a required column on the entity; ZTag + SAPID skipped when null to avoid empty-string property noise); IdentificationFolderBuilder.Build materializes the OPC 40010 sub-folder when HasAnyFields(equipment) returns true, skipped otherwise to avoid a pointless empty folder; then one Variable node per Tag row bound to this Equipment (Tag.EquipmentId non-null matches Equipment.EquipmentId) emitted in Name order. Tags with null EquipmentId are walker-skipped — those are SystemPlatform-kind (Galaxy) tags that take the driver-native DiscoverAsync path per decision #120. DriverAttributeInfo construction: FullName = Tag.TagConfig (driver-specific wire-level address); DriverDataType parsed from Tag.DataType which stores the enum name string per decision #138; unparseable values fall back to DriverDataType.String so a one-off driver-specific type doesn't abort the whole walk (driver still sees the original address at runtime + can surface its own typed value via the variant). Address validation is deliberately NOT done at build time per ADR-001 Option A: unreachable addresses surface as OPC UA Bad status via the natural driver-read failure path at runtime, legible to operators through their Admin UI + OPC UA client inspection. Eight new EquipmentNodeWalkerTests: empty content emits nothing; Area/Line/Equipment folder emission order matches Name-sorted deterministic traversal; five identifier properties appear on Equipment nodes with correct values, ZTag + SAPID skipped when null + emitted when non-null; Identification sub-folder materialized when at least one OPC 40010 field is non-null + omitted when all are null; tags with matching EquipmentId emit as Variable nodes under the Equipment folder in Name order, tags with null EquipmentId walker-skipped; unparseable DataType falls back to String. RecordingBuilder test double captures Folder/Variable/Property calls into a tree structure tests can navigate. Core project builds 0 errors; Core.Tests 190/190 (was 182, +8 new walker tests). No Server/Admin changes — Task B lands the server-side wiring + consumes this walker from DriverNodeManager.
AB CIP Logix Emulate golden-box tier — scaffold the code + docs so the L5X + Emulate PC drop in without fixture-code changes. Closes the initial design question the user raised; the actual Emulate-side work (author project, commit L5X, install Emulate on the dev box) is tracked as #223. Scaffolding ships everything that doesn't need the live Emulate instance: tier-gated test classes that skip cleanly when
AB_SERVER_PROFILE is unset, the profile gate helper, the LogixProject/README.md documenting the exact project state the tests expect, the fixture coverage doc's new §Logix Emulate tier section with the when-to-trust table extended from 3 columns to 4, and the dev-environment.md integration-host row.
AbCip IAlarmSource via ALMD projection (#177) — feature-flagged OFF by default; when enabled, polls declared ALMD UDT member fields + raises OnAlarmEvent on 0→1 + 1→0 transitions. Closes task #177. The AB CIP driver now implements IAlarmSource so the generic-driver alarm dispatch path (PR 14's sinks + the Server.Security.AuthorizationGate AlarmSubscribe/AlarmAck invoker wrapping) can treat AB-backed alarms uniformly with Galaxy + OpcUaClient + FOCAS. Projection is ALMD-only in this pass: the Logix ALMD (digital alarm) instruction's UDT shape is well-understood (InFaulted + Acked + Severity + In + Cfg_ProgTime at stable member names) so the polled-read + state-diff pattern fits without concessions. ALMA (analog alarm) deferred to a follow-up because its HHLimit/HLimit/LLimit/LLLimit threshold + In value semantics deserve their own design pass — raising on threshold-crossing is not the same shape as raising on InFaulted-edge. AbCipDriverOptions gains two knobs: EnableAlarmProjection (default false) + AlarmPollInterval (default 1s). Explicit opt-in because projection semantics don't exactly mirror Rockwell FT Alarm & Events; shops running FT Live should leave this off + take alarms through the native A&E route. AbCipAlarmProjection is the state machine: per-subscription background loop polls the source-node set via the driver's public ReadAsync — which gains the #194 whole-UDT optimization for free when ALMDs are declared with their standard member set, so one poll tick reads (N alarms × 2 members) = N libplctag round-trips rather than 2N. Per-tick state diff: compare InFaulted + Severity against last-seen, fire raise (0→1) / clear (1→0) with AlarmSeverity bucketed via the 1-1000 Logix severity scale (≤250 Low, ≤500 Medium, ≤750 High, rest Critical — matches OpcUaClient's MapSeverity shape). ConditionId is {sourceNode}#active — matches a single active-branch per alarm which is all ALMD supports; when Cfg_ProgTime-based branch identity becomes interesting (re-raise after ack with new timestamp), a richer ConditionId pass can land. Subscribe-while-disabled returns a handle wrapping id=0 — capability negotiation (the server queries IAlarmSource presence at driver-load time) still succeeds, the alarm surface just never fires. Unsubscribe cancels the sub's CTS + awaits its loop; ShutdownAsync cancels every sub on its way out so a driver reload doesn't leak poll tasks. AcknowledgeAsync routes through the driver's existing WriteAsync path — per-ack writes {SourceNodeId}.Acked = true (the simpler semantic; operators whose ladder watches AckCmd + rising-edge can wire a client-side pulse until a driver-level edge-mode knob lands). Best-effort — per-ack faults are swallowed so one bad ack doesn't poison the whole batch. Six new AbCipAlarmProjectionTests: detector flags ALMD signature + skips non-signature UDTs + atomics; severity mapping matches OPC UA A&C bucket boundaries; feature-flag OFF returns a handle but never touches the fake runtime (proving no background polling happens); feature-flag ON fires a raise event on 0→1; clear event fires on 1→0 after a prior raise; unsubscribe stops the poll loop (ReadCount doesn't grow past cancel + at most one straggler read). Driver builds 0 errors; AbCip.Tests 233/233 (was 227, +6 new). Task #177 closed — the last pending AB CIP follow-up is now #194 (already shipped). Remaining pending fleet-wide: #150 (Galaxy MXAccess failover hardware) + #199 (UnsTab Playwright smoke).
AB Legacy ab_server PCCC Docker fixture scaffold (#224) — Docker infrastructure + test-class shape in place; wire-level round-trip currently blocked by an ab_server-side PCCC coverage gap documented honestly in the fixture + coverage docs. Closes the Docker-infrastructure piece of #224; the remaining work is upstream (patch ab_server's PCCC server opcodes) or sideways (RSEmulate 500 golden-box tier, lab rig).
RMW pass 2 — AbCip BOOL-within-DINT + AbLegacy bit-within-word. Closes task #181. AbCip — AbCipDriver.WriteAsync now detects BOOL writes with a bit index + routes them through WriteBitInDIntAsync: strip the .N suffix to form the parent DINT tag path (via AbCipTagPath with BitIndex=null + ToLibplctagName), get/create a cached parent IAbCipTagRuntime via EnsureParentRuntimeAsync (distinct from the bit-selector tag runtime so read + write target the DINT directly), acquire a per-parent-name SemaphoreSlim, Read → Convert.ToInt32 the current DINT → (current | 1<<bit) or (current & ~(1<<bit)) → Write via EncodeValue(DInt, updated). Per-parent lock prevents concurrent writers to the same DINT from losing updates — parallels Modbus + FOCAS pass 1. DeviceState gains ParentRuntimes dict + GetRmwLock helper + _rmwLocks ConcurrentDictionary. DisposeHandles now walks ParentRuntimes too. LibplctagTagRuntime.EncodeValue's BOOL-with-bitIndex branch stays as a defensive throw (message updated to point at the new driver-level dispatch) so an accidental bypass fails loudly rather than silently clobbering the whole DINT. AbLegacy — identical pattern for PCCC N-file bit writes. AbLegacyDriver.WriteAsync detects Bit with bitIndex + PMC letter not in {B, I, O} (B-file + I/O use their own bit-addressable semantics so don't RMW at N-file word level), routes through WriteBitInWordAsync which uses Int16 for the parent word, creates + caches a parent runtime with the suffix-stripped N7:0 address, acquires per-parent lock, RMW. DeviceState extended the same way as AbCip (ParentRuntimes + GetRmwLock). LibplctagLegacyTagRuntime.EncodeValue Bit-with-bitIndex branch points at the driver dispatch. Tests — 5 new AbCipBoolInDIntRmwTests (bit set ORs + preserves, bit clear ANDs + preserves, 8-way concurrent writes to same parent compose to 0xFF, different-parent writes get separate runtimes, repeat bit writes reuse the parent runtime init-count 1 + write-count 2), 4 new AbLegacyBitRmwTests (bit set preserves, bit clear preserves 0xFFF7, 8-way concurrent 0xFF, repeat writes reuse parent). Two pre-existing tests flipped — AbCipDriverWriteTests.Bit_in_dint_write_returns_BadNotSupported + AbLegacyReadWriteTests.Bit_within_word_write_rejected_as_BadNotSupported both now assert Good instead of BadNotSupported, renamed to _now_succeeds_via_RMW. Total tests — AbCip 166/166, AbLegacy 96/96, full solution builds 0 errors; Modbus + FOCAS + TwinCAT + other drivers untouched. Task #181 done across all four libplctag-backed + non-libplctag drivers (Modbus BitInRegister + AbCip BOOL-in-DINT + AbLegacy N-file bit + FOCAS PMC Bit — all with per-parent-word serialisation).
FOCAS Tier-C PR E — ops glue: ProcessHostLauncher + post-mortem MMF + NSSM install scripts + doc close-out. Final of the 5 PRs for #220. With this landing, the Tier-C architecture is fully shipped; the only remaining FOCAS work is the hardware-dependent FwlibHostedBackend (real Fwlib32.dll P/Invoke, gated on #222 lab rig).
FOCAS Tier-C PR A — Driver.FOCAS.Shared MessagePack IPC contracts. First PR of the 5-PR #220 split (isolation plan at docs/v2/implementation/focas-isolation-plan.md). Adds a new netstandard2.0 project consumable by both the .NET 10 Proxy and the future .NET 4.8 x86 Host, carrying every wire DTO the Proxy <-> Host pair will exchange: Hello/HelloAck + Heartbeat/HeartbeatAck + ErrorResponse for session negotiation (shared-secret + protocol major/minor mirroring Galaxy.Shared); OpenSessionRequest/Response + CloseSessionRequest carrying the declared FocasCncSeries so the Host picks up the pre-flight matrix; FocasAddressDto + FocasDataTypeCode for wire-compatible serialization of parsed addresses (0=Pmc/1=Param/2=Macro matches FocasAreaKind enum order so both sides cast (int)); ReadRequest/Response + WriteRequest/Response with MessagePack-serialized boxed values tagged by FocasDataTypeCode; PmcBitWriteRequest/Response as a first-class RMW operation so the critical section stays Host-side; Subscribe/Unsubscribe/OnDataChangeNotification for poll-loop-pushes-deltas model (FOCAS has no CNC-initiated callbacks); Probe + RuntimeStatusChange + Recycle surface for Tier-C supervision. Framing is [4-byte BE length][1-byte kind][body] with 16 MiB body cap matching Galaxy; FocasMessageKind byte values align with Galaxy ranges so an operator reading a hex dump doesn't have to context-switch. FrameReader/FrameWriter ported from Galaxy.Shared with thread-safe concurrent-write serialization. 24 new unit tests: 18 per-DTO round-trip tests covering every field + 6 framing tests (single-frame round-trip, clean-EOF returns null, oversized-length rejection, mid-frame EOF throws, 20-way concurrent-write ordering preserved, MessageKind byte values locked as wire-stable). No driver changes; existing 165 FOCAS unit tests still pass unchanged. PR B (Host skeleton) goes next.
FOCAS Tier-C PR E — ops glue: ProcessHostLauncher + post-mortem MMF + NSSM install scripts + doc close-out. Final of the 5 PRs for #220. With this landing, the Tier-C architecture is fully shipped; the only remaining FOCAS work is the hardware-dependent FwlibHostedBackend (real Fwlib32.dll P/Invoke, gated on #222 lab rig).
Phase 3 PR 40 — LiveStackSmokeTests: write-roundtrip + subscribe-receives-OnDataChange against the live Galaxy. Finishes LMX #5 by exercising the IWritable + ISubscribable capability paths end-to-end through the Proxy → OtOpcUaGalaxyHost service → MXAccess → real Galaxy.
Phase 1 Streams B–E scaffold + Phase 2 Streams A–C scaffold — 8 new projects with ~70 new tests, all green alongside the 494 v1 IntegrationTests baseline (parity preserved: no v1 tests broken; legacy OtOpcUa.Host untouched). Phase 1 finish: Configuration project (16 entities + 10 enums + DbContext + DesignTimeDbContextFactory + InitialSchema/StoredProcedures/AuthorizationGrants migrations — 8 procs including sp_PublishGeneration with MERGE on ExternalIdReservation per decision #124, sp_RollbackToGeneration cloning rows into a new published generation, sp_ValidateDraft with cross-cluster-namespace + EquipmentUuid-immutability + ZTag/SAPID reservation pre-flight, sp_ComputeGenerationDiff with CHECKSUM-based row signature — plus OtOpcUaNode/OtOpcUaAdmin SQL roles with EXECUTE grants scoped to per-principal-class proc sets and DENY UPDATE/DELETE/INSERT/SELECT on dbo schema); managed DraftValidator covering UNS segment regex, path length, EquipmentUuid immutability across generations, same-cluster namespace binding (decision #122), reservation pre-flight, EquipmentId derivation (decision #125), driver↔namespace compatibility — returning every failing rule in one pass; LiteDB local cache with round-trip + ring pruning + corruption-fast-fail; GenerationApplier with per-entity Added/Removed/Modified diff and dependency-ordered callbacks (namespace → driver → device → equipment → poll-group → tag, Removed before Added); Core project with GenericDriverNodeManager (scaffold for the Phase 2 Galaxy port) and DriverHost lifecycle registry; Server project using Microsoft.Extensions.Hosting BackgroundService replacing TopShelf, with NodeBootstrap that falls back to LiteDB cache when the central DB is unreachable (decision #79); Admin project scaffolded as Blazor Server with Bootstrap 5 sidebar layout, cookie auth, three admin roles (ConfigViewer/ConfigEditor/FleetAdmin), Cluster + Generation services fronting the stored procs. Phase 2 scaffold: Driver.Galaxy.Shared (netstandard2.0) with full MessagePack IPC contract surface — Hello version negotiation, Open/CloseSession, Heartbeat, DiscoverHierarchy + GalaxyObjectInfo/GalaxyAttributeInfo, Read/WriteValues, Subscribe/Unsubscribe/OnDataChange, AlarmSubscribe/Event/Ack, HistoryRead, HostConnectivityStatus, Recycle — plus length-prefixed framing (decision #28) with a 16 MiB cap and thread-safe FrameWriter/FrameReader; Driver.Galaxy.Host (net48) implementing the Tier C cross-cutting protections from driver-stability.md — strict PipeAcl (allow configured server SID only, explicit deny on LocalSystem + Administrators), PipeServer with caller-SID verification via pipe.RunAsClient + WindowsIdentity.GetCurrent and per-process shared-secret Hello, Galaxy-specific MemoryWatchdog (warn at max(1.5×baseline, +200 MB), soft-recycle at max(2×baseline, +200 MB), hard ceiling 1.5 GB, slope ≥5 MB/min over 30-min rolling window), RecyclePolicy (1 soft recycle per hour cap + 03:00 local daily scheduled), PostMortemMmf (1000-entry ring buffer in %ProgramData%\OtOpcUa\driver-postmortem\galaxy.mmf, survives hard crash, readable cross-process), MxAccessHandle : SafeHandle (ReleaseHandle loops Marshal.ReleaseComObject until refcount=0 then calls optional unregister callback), StaPump with responsiveness probe (BlockingCollection dispatcher for Phase 1 — real Win32 GetMessage/DispatchMessage pump slots in with the same semantics when the Galaxy code lift happens), IsExternalInit shim for init setters on .NET 4.8; Driver.Galaxy.Proxy (net10) implementing IDriver + ITagDiscovery forwarding over the IPC channel with MX data-type and security-classification mapping, plus Supervisor pieces — Backoff (5s → 15s → 60s capped, reset-on-stable-run), CircuitBreaker (3 crashes per 5 min opens; 1h → 4h → manual cooldown escalation; sticky alert doesn't auto-clear), HeartbeatMonitor (2s cadence, 3 consecutive misses = host dead per driver-stability.md). Infrastructure: docker SQL Server remapped to host port 14330 to coexist with the native MSSQL14 Galaxy ZB DB instance on 1433; NuGetAuditSuppress applied per-project for two System.Security.Cryptography.Xml advisories that only reach via EF Core Design with PrivateAssets=all (fix ships in 11.0.0-preview); .slnx gains 14 project registrations. Deferred with explicit TODOs in docs/v2/implementation/phase-2-partial-exit-evidence.md: Phase 1 Stream E Admin UI pages (Generations listing + draft-diff-publish, Equipment CRUD with OPC 40010 fields, UNS Areas/Lines tabs, ACLs + permission simulator, Generic JSON config editor, SignalR real-time, Release-Reservation + Merge-Equipment workflows, LDAP login page, AppServer smoke test per decision #142), Phase 2 Stream D (Galaxy MXAccess code lift out of legacy OtOpcUa.Host, dual-service installer, appsettings → DriverConfig migration script, legacy Host deletion — blocked by parity), Phase 2 Stream E (v1 IntegrationTests against v2 topology, Client.CLI walkthrough diff, four 2026-04-13 stability findings regression tests, adversarial review — requires live MXAccess runtime).
RMW pass 1 — Modbus BitInRegister + FOCAS PMC Bit write paths. First half of task #181 — the two drivers where read-modify-write is a clean protocol-level insertion (Modbus FC03/FC06 round-trip + FOCAS pmc_rdpmcrng / pmc_wrpmcrng round-trip). Per-driver SemaphoreSlim registry keyed on the parent word address serialises concurrent bit writes so two writers targeting different bits in the same word don't lose one another's update. Modbus — ModbusDriver gains WriteBitInRegisterAsync + _rmwLocks ConcurrentDictionary. WriteOneAsync routes BitInRegister (HoldingRegisters region only) through RMW ahead of the normal encode path. Read uses FC03 Read Holding Registers for 1 register at tag.Address, bit-op on the returned ushort via (current | 1<<bit) for set / (current & ~(1<<bit)) for clear, write back via FC06 Write Single Register. Per-address lock prevents concurrent bit writes to the same register from racing. Rejects out-of-range bits (0-15) with InvalidOperationException. EncodeRegister's BitInRegister branch repurposed as a defensive guard — if a non-RMW caller ever reaches it, throw so an unintended bypass stays loud rather than silently clobbering. FOCAS — FwlibFocasClient gains WritePmcBitAsync + _rmwLocks keyed on {addrType}:{byteAddr}. Driver-layer WriteAsync routes Bit writes with a bitIndex through the new path; other Pmc writes still hit the direct pmc_wrpmcrng path. RMW uses cnc_rdpmcrng + Byte dataType to grab the parent byte, bit-op with (current | 1<<bit) or (current & ~(1<<bit)), cnc_wrpmcrng to write back. Rejects out-of-range bits (0-7, FOCAS PMC bytes are 8-bit) with InvalidOperationException. EncodePmcValue's Bit branch now treats a no-bitIndex case as whole-byte boolean (non-zero / zero); bitIndex-present writes never hit this path because they dispatch to WritePmcBitAsync upstream. Tests — 5 new ModbusBitRmwTests + 4 new FocasPmcBitRmwTests + 1 renamed pre-existing test each covering — bit set preserves other bits, bit clear preserves other bits, concurrent bit writes to same word/byte compose correctly (8-parallel stress), bit writes on different parent words proceed without contention (4-parallel), sequential bit sets compose into 0xFF after all 8. Fake PmcRmwFake in FOCAS tests simulates the PMC byte storage + surfaces it through the IFocasClient contract so the test asserts driver-level behavior without needing Fwlib32.dll. FwlibNativeHelperTests.EncodePmcValue_Bit_throws_NotSupported_for_RMW_gap replaced with EncodePmcValue_Bit_without_bit_index_writes_byte_boolean reflecting the new behavior. ModbusDataTypeTests.BitInRegister_write_is_not_supported_in_PR24 renamed to BitInRegister_EncodeRegister_still_rejects_direct_calls; the message assertion updated to match the new defensive message. Modbus tests now 182/182, FOCAS tests now 119/119; full solution builds 0 errors; AbCip/AbLegacy/TwinCAT untouched (those get their RMW pass in a follow-up since libplctag bit access may need a parallel parent-word handle). Task #181 stays pending until that second pass lands.
OpcUaClient integration fixture — opc-plc in Docker closes the wire-level gap (#215). Closes task #215. The OpcUaClient driver had the richest capability matrix in the fleet (reads/writes/subscribe/alarms/history across 11 unit-test classes) + zero wire-level coverage; every test mocked the Session surface. opc-plc is Microsoft Industrial IoT's OPC UA PLC simulator — already containerized, already on MCR, pinned to 2.14.10 here. Wins vs the loopback-against-our-own-server option we'd originally scoped: (a) independent cert chain + user-token handling catches interop bugs loopback can't because both endpoints would share our own cert store; (b) pinned image tag fixes the test surface in a way our evolving server wouldn't; (c) the --alm flag opens the door to real IAlarmSource coverage later without building a custom FakeAlarmDriver. Loss vs loopback: both use the OPCFoundation.NetStandard stack internally so bugs common to that stack don't surface — addressed by a follow-up to add open62541/open62541 as a second independent-stack image (tracked). Docker is the fixture launcher — no PowerShell/Python wrapper like Modbus/pymodbus or S7/python-snap7 because opc-plc ships containerized. Docker/docker-compose.yml pins 2.14.10 + maps port 50000 + command flags --pn=50000 --ut --aa --alm; the healthcheck TCP-probes 50000 so
docker ps surfaces ready state. Fixture OpcPlcFixture follows the same shape as Snap7ServerFixture + ModbusSimulatorFixture: collection-scoped, parses OPCUA_SIM_ENDPOINT (default opc.tcp://localhost:50000) into host + port, 2-second TCP probe at init, SkipReason records the failure for Assert.Skip. Forced IPv4 on the probe socket for the same reason those two fixtures do — .NET's dual-stack "localhost" resolves IPv6 ::1 first + hangs the full connect timeout when the target binds 0.0.0.0 (IPv4). OpcPlcProfile holds well-known node identifiers opc-plc exposes (ns=3;s=StepUp, FastUInt1, RandomSignedInt32, AlternatingBoolean) + builds OpcUaClientDriverOptions with SecurityPolicy.None + AutoAcceptCertificates=true since opc-plc regenerates its server cert on every container spin-up + there's no meaningful chain to validate against in CI. Three smoke tests covering what the unit suite couldn't reach: (1) Client_connects_and_reads_StepUp_node_through_real_OPC_UA_stack — full Secure Channel + Session + Read on ns=3;s=StepUp (counter that ticks every 1 s); (2) Client_reads_batch_of_varied_types_from_live_simulator — batch Read of UInt32 / Int32 / Boolean to prove typed Variant decoding, with an explicit ShouldBeOfType<bool> assertion on AlternatingBoolean to catch the common "variant gets stringified" regression; (3) Client_subscribe_receives_StepUp_data_changes_from_live_server — real MonitoredItem subscription on FastUInt1 (100 ms cadence) with a SemaphoreSlim gate + 3 s deadline on the first OnDataChange fire, tolerating container warm-up. Driver ran end-to-end against a live 2.14.10 container: all 3 pass; unit suite 78/78 unchanged. Container lifecycle verified (compose up → tests → compose down) clean, no leaked state. Docker/README.md documents install (Docker Desktop already on the dev box per Phase 1 decision #134), run (compose up / compose up -d / compose down), endpoint override (OPCUA_SIM_ENDPOINT), what opc-plc advertises with the current command flags, what's tunable via compose-file tweaks (--daa for username auth tests; --fn/--fr/--ft for subscription-stress nodes), known limitation that opc-plc shares the OPCFoundation stack with our driver. OpcUaClient-Test-Fixture.md updated — TL;DR flipped from "there is no integration fixture" to the new reality; "What it actually covers" gains an Integration section listing the three smoke tests. Follow-up the doc flags: add open62541/open62541 as a second image for fully-independent-stack interop coverage; once #219 (server-side IAlarmSource/IHistoryProvider integration tests) lands, re-run the client-side suite against opc-plc's --alm nodes to close the alarm gap from the client side too.
TwinCAT XAR integration fixture — scaffold the code + docs so the Hyper-V VM + .tsproj drop in without fixture-code changes. Mirrors the AB CIP Logix Emulate scaffold shipped in PR #165: tier-gated smoke tests that skip cleanly when the VM isn't reachable, a project README documenting exactly what the XAR needs to run, fixture-coverage doc promoting TwinCAT from "no integration fixture" to "scaffolded + needs operational setup". The actual Beckhoff-side work (provision VM, install XAR, author tsproj, rotate 7-day trial) lives in #221 + the new TwinCatProject/README.md walkthrough.
TwinCAT follow-up — Symbol browser via AdsClient + SymbolLoaderFactory. Closes task #188. Adds ITwinCATClient.BrowseSymbolsAsync — IAsyncEnumerable yielding TwinCATDiscoveredSymbol (InstancePath + mapped TwinCATDataType + ReadOnly flag) from the target's flat symbol table. AdsTwinCATClient implementation uses SymbolLoaderFactory.Create(_client, new SymbolLoaderSettings(SymbolsLoadMode.Flat)) + iterates loader.Symbols, maps IEC 61131-3 type names (BOOL/SINT/INT/DINT/LINT/REAL/LREAL/STRING/WSTRING/TIME/DATE/DT/TOD + BYTE/WORD/DWORD/LWORD unsigned-word aliases) through MapSymbolTypeName, checks SymbolAccessRights.Write bit for writable vs read-only. Unsupported types (UDTs / function blocks / arrays / pointers) surface with DataType=null so callers can skip or recurse. TwinCATDriverOptions.EnableControllerBrowse — new bool, default false to preserve the strict-config path. When true, DiscoverAsync iterates each device's BrowseSymbolsAsync, filters via TwinCATSystemSymbolFilter (rejects TwinCAT_*, Constants.*, Mc_*, __*, Global_Version* prefixes + anything empty), skips null-DataType symbols, emits surviving symbols under a per-device Discovered/ sub-folder with InstancePath as both FullName + BrowseName + ReadOnly→ViewOnly/writable→Operate. Pre-declared tags from TwinCATDriverOptions.Tags always emit regardless. Browse failure is non-fatal — exception caught + swallowed, pre-declared tags stay in the address space, operators see the failure in driver health on next read. TwinCATSystemSymbolFilter static class mirrors AbCipSystemTagFilter's shape with TwinCAT-specific prefixes. Fake client updated — BrowseResults list for test setup + FireNotification-style single-invocation on each subscribe, ThrowOnBrowse flag for failure testing. 8 new unit tests — strict path emits only pre-declared when EnableControllerBrowse=false, browse enabled adds Discovered/ folder, filter rejects system prefixes, null-DataType symbols skipped, ReadOnly symbols surface ViewOnly, browse failure leaves pre-declared intact, SystemSymbolFilter theory (10 cases). Total TwinCAT unit tests now 110/110 passing (+17 from the native-notification merge's 93); full solution builds 0 errors; other drivers untouched.
ADR-001 last-mile — Program.cs composes EquipmentNodeWalker into the production boot path. Closes task #214 + fully lands ADR-001 Option A as a live code path, not just a connected set of unit-tested primitives. After this PR a server booted against a real Config DB with Published Equipment rows materializes the UNS tree into the OPC UA address space on startup — the whole walker → wire-in → loader chain (PRs #153, #154, #155, #156) finally fires end-to-end in the production process. DriverEquipmentContentRegistry is the handoff between OpcUaServerService's bootstrap-time populate pass + OpcUaApplicationHost's StartAsync walker invocation. It's a singleton mutable holder with Get/Set/Count + Lock-guarded internal dictionary keyed OrdinalIgnoreCase to match the DriverInstanceId convention used by Equipment / Tag rows + walker grouping. Set-once-per-bootstrap semantics in practice though nothing enforces that at the type level — OpcUaServerService.PopulateEquipmentContentAsync is the only expected writer. Shared-mutable rather than immutable-passed-by-value because the DI graph builds OpcUaApplicationHost before NodeBootstrap has resolved the generation, so the registry must exist at compose time + fill at boot time. Program.cs now registers OpcUaApplicationHost via a factory lambda that threads registry.Get as the equipmentContentLookup delegate PR #155 added to the ctor seam — the one-line composition the earlier PR promised. EquipmentNamespaceContentLoader (from PR #156) is AddScoped since it takes the scoped OtOpcUaConfigDbContext; the populate pass in OpcUaServerService opens one IServiceScopeFactory scope + reuses the same loader + DbContext across every driver query rather than scoping-per-driver. OpcUaServerService.ExecuteAsync gets a new PopulateEquipmentContentAsync step between bootstrap + StartAsync: iterates DriverHost.RegisteredDriverIds, calls loader.LoadAsync per driver at the bootstrapped generationId, stashes non-null results in the registry. Null results are skipped — the wire-in's null-check treats absent registry entries as "this driver isn't Equipment-kind; let DiscoverAsync own the address space" which is the correct backward-compat path for Modbus / AB CIP / TwinCAT / FOCAS. Guarded on result.GenerationId being non-null — a fleet with no Published generation yet boots cleanly into a UNS-less address space and fills the registry on the next restart after first publish. Ctor on OpcUaServerService gained two new dependencies (DriverEquipmentContentRegistry + IServiceScopeFactory). No test file constructs OpcUaServerService directly so no downstream test breakage — the BackgroundService is only wired via DI in Program.cs. Four new DriverEquipmentContentRegistryTests: Get-null-for-unknown, Set-then-Get, case-insensitive driver-id lookup, Set-overwrites-existing. Server.Tests 190/190 (was 186, +4 new registry tests). Full ADR-001 Option A now lives at every layer: Core.OpcUa walker (#153) → ScopePathIndexBuilder (#154) → OpcUaApplicationHost wire-in (#155) → EquipmentNamespaceContentLoader (#156) → this PR's registry + Program.cs composition. The last pending loose end (full-integration smoke test that boots Program.cs against a seeded Config DB + verifies UNS tree via live OPC UA client) isn't strictly necessary because PR #155's OpcUaEquipmentWalkerIntegrationTests already proves the wire-in at the OPC UA client-browse level — the Program.cs composition added here is purely mechanical + well-covered by the four-file audit trail plus registry unit tests.