chore(localdb): phase-2 DoD sweep

Build: 0 errors solution-wide, and 0 warnings from every project this branch
touches. The ~816 solution-wide warnings are pre-existing xUnit1051 /
OTOPCUA0001 / CS86xx in untouched driver + client test projects.

Tests: full solution run compared against a full run on a detached worktree at
the pre-branch baseline 2e46d054. The two failure SETS are identical -- all 13
tests, same names, zero new failures. Net +26 tests: +3 Core.AlarmHistorian
(drain gate), +6 Runtime (role view), +17 Host.IntegrationTests (migrator +
convergence). Set comparison rather than counts, because the suite carries
standing environment- and load-dependent failures a count would hide.

The greps found real drift Task 6 missed -- eight live sites still naming the
deleted SqliteStoreAndForwardSink, including the AdminUI /alarms/historian
panel text, which is user-visible, and a <see cref> in HistorianAdapterActor
that resolved to nothing without warning. All repointed at
LocalDbStoreAndForwardSink; CLAUDE.md's alarm-history paragraph now also
records the LocalDb buffer and the primary-gated drain, and drops DatabasePath
from the knob list. docs/AlarmTracking.md still promised an
AlarmHistorianOptions.Validate() startup warning for a relative DatabasePath
and an empty SharedSecret; both branches are gone, so it now says so.

Code references to AlarmHistorian:DatabasePath reduce to exactly two intentional
ones: AlarmSfLegacyMigrator.LegacyPathKey and its test. No `new SqliteConnection`
remains anywhere in Core.AlarmHistorian.

Recon doc gains the durable verification record: guard-deletion evidence for
both vacuous passes, the two exact-set replicated-table pins (both assert set
equality, so an added or a dropped registration fails), and the baseline test
comparison with a per-failure account of why each of the 13 is not this
branch's.

Stops here per the plan. Task 8's live gate needs explicit go-ahead; nothing on
this branch is to be merged.

Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/AlarmsHistorian.razor

@@ -18,8 +18,9 @@
 <section class="panel notice rise" style="animation-delay:.02s">
     Snapshot from the local node's <span class="mono">HistorianAdapterActor</span>. Default sink
     is a no-op (<span class="mono">NullAlarmHistorianSink</span>); production wires
-    <span class="mono">SqliteStoreAndForwardSink</span> draining to the HistorianGateway
-    (<span class="mono">SendEvent</span>) behind it. Polling every @PollSeconds s.
+    <span class="mono">LocalDbStoreAndForwardSink</span> — buffering into this node's LocalDb, and
+    draining to the HistorianGateway (<span class="mono">SendEvent</span>) only while this node holds
+    the Primary role. Polling every @PollSeconds s.
 </section>
 
 @if (_status is null)

src/Server/ZB.MOM.WW.OtOpcUa.Host/Program.cs

@@ -136,7 +136,7 @@ if (hasDriver)
 
     // Config-gated durable alarm-historian sink. When the AlarmHistorian section is enabled this
     // overrides the NullAlarmHistorianSink default from AddOtOpcUaRuntime (last registration wins)
-    // with a SqliteStoreAndForwardSink draining to the gateway SendEvent writer. The alarm-write path
+    // with a LocalDbStoreAndForwardSink draining to the gateway SendEvent writer. The alarm-write path
     // targets the SAME single gateway as the read path, so its connection (endpoint/key/TLS) is sourced
     // from the ServerHistorian section. AlarmHistorianOptions supplies only the Enabled gate + the
     // SQLite store-and-forward knobs (consumed inside AddAlarmHistorian) — it carries no connection fields.

src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Historian/HistorianAdapterActor.cs

@@ -15,7 +15,7 @@ namespace ZB.MOM.WW.OtOpcUa.Runtime.Historian;
 /// Thin actor wrapper around <see cref="IAlarmHistorianSink"/>. Engine code (ScriptedAlarmActor,
 /// Galaxy native alarm bridge, AB CIP ALMD reader) tells <see cref="AlarmHistorianEvent"/>s to this
 /// actor; the actor enqueues them on the sink fire-and-forget. Production deployments register
-/// <see cref="SqliteStoreAndForwardSink"/> against <c>IAlarmHistorianSink</c>; the sink owns the
+/// <see cref="LocalDbStoreAndForwardSink"/> against <c>IAlarmHistorianSink</c>; the sink owns the
 /// durable queue + drain-to-HistorianGateway-SendEvent loop. The actor here owns nothing operational beyond
 /// the message contract — its job is to keep the engine actors on Akka's mailbox without blocking
 /// them on disk I/O or gateway round-trips.

src/Server/ZB.MOM.WW.OtOpcUa.Runtime/ServiceCollectionExtensions.cs

@@ -41,7 +41,7 @@ public static class ServiceCollectionExtensions
     /// <summary>
     /// Registers shared runtime services. Currently binds <see cref="IAlarmHistorianSink"/>
     /// to <see cref="NullAlarmHistorianSink"/> as the default; production deployments
-    /// override this with <c>SqliteStoreAndForwardSink</c> wrapping the HistorianGateway alarm writer.
+    /// override this with <c>LocalDbStoreAndForwardSink</c> wrapping the HistorianGateway alarm writer.
     /// Call this BEFORE <c>AddAkka</c>.
     /// </summary>
     /// <param name="services">The service collection to register with.</param>