Resolve all 33 medium-severity architecture review findings

Second slice of the 2026-09-09 whole-system review remediation
(docs/plans/2026-09-09-arch-review.md §10), on top of the High slice 146a1323.

Runtime/devices: SR-2 alarm on-trigger integration scope; SR-3 correlated NativeAlarmActor
subscribe retry; SR-4 immutable audited DB target; SR-5 ordered InstanceActor stop/flush;
SR-12 rehydration fence; SR-13 S&F gate recheck per delivery; DC-4 no OPC UA security
downgrade; DC-5 alarm snapshot for every new subscriber; ORCH-1 sync-dispose joins the pump.

Management/UI: MG-2 site scope on audit tree + Flow Debugger Replay; MG-3 stale-probe memo
removed; MG-4 server-owned bulk-deploy deadline; UI-5 sandbox runs in a killable child
process (new CentralUI.SandboxWorker project); UI-14 bounded sandbox output/IPC.

Edge/audit: EI-1 relay audit ownership; EI-2 SkipBodyCapture suppresses error text; EI-3/EI-11
error-field redaction + caps; EI-4 single relay deadline, pre-execution-only retry; EI-5
authenticated relay provenance; EI-10 body cap before audit read.

Persistence/contracts: DL-1 global Instance.UniqueName unique index + conflict translation;
DL-2 DataConnection protocol config encrypted at rest (migration
20260909203046_EnforceGlobalInstanceNamesAndProtectProtocolConfiguration — coordinated
central upgrade, old binaries cannot read protected rows); DL-3 bounded Replay paging;
DL-6 cross-site Overwrite of a deployed instance rejected; XC-4 proto descriptor contract test.

Config/hygiene: XC-1 central listener isolation by local port; XC-2/XC-3 inert SMTP + cron
keys removed from rig settings; CM-2 env2 bootstrap guard enabled; DC-6 deploy site exit code;
DC-7 notifier retries only explicit standby rejection; XC-5 ClusterClient purged from docs.

Gates recorded in the report: build 0/0, 9 397 passed / 0 failed, rig redeployed on all
eight nodes with the migration applied. 46 Low findings remain open.

src/ZB.MOM.WW.ScadaBridge.SiteRuntime/Tracking/OperationTrackingStore.cs

@@ -612,30 +612,11 @@ public class OperationTrackingStore : IOperationTrackingStore, IAsyncDisposable,
     /// Synchronously disposes the tracking store and its SQLite connection.
     /// </summary>
     /// <remarks>
-    /// This path does NOT bridge to async via
-    /// <c>.AsTask().GetAwaiter().GetResult()</c>. Sync-over-async on a SemaphoreSlim
-    /// can deadlock when invoked from a non-reentrant SyncContext (e.g. host
-    /// shutdown continuations observed on the host sync context). In-flight writes
-    /// at the moment of <see cref="Dispose"/> will fail their next operation
-    /// against the disposed connection with <see cref="ObjectDisposedException"/> —
-    /// the caller's responsibility is to ensure no concurrent operations during
-    /// the synchronous dispose. Use <see cref="DisposeAsync"/> if you need to
-    /// drain in-flight writes before close.
+    /// The pump runs on the thread pool and its drain does not capture a caller's
+    /// synchronization context. Join it before releasing SQLite resources, exactly
+    /// as the asynchronous path does; never close a live writer transaction.
     /// </remarks>
-    public void Dispose()
-    {
-        if (Interlocked.Exchange(ref _disposeState, 1) != 0)
-        {
-            return;
-        }
-
-        // Stop accepting work; whatever is still queued fails on the pump with
-        // ObjectDisposedException (see ApplyBatch) — this path does not drain.
-        _queue.Writer.TryComplete();
-        _writeConnection.Dispose();
-        _writeGate.Dispose();
-        GC.SuppressFinalize(this);
-    }
+    public void Dispose() => DisposeAsync().AsTask().GetAwaiter().GetResult();
 
     /// <summary>
     /// Asynchronously disposes the tracking store and its SQLite connection.