merge(agent-a): rows 85+83 — EnsureDclConnections moved into the CreateInstanceActor funnel (self-healed/enabled instances get their DCL connections); ReconcileStartsInstanceTests gated on first instance-count report

src/ZB.MOM.WW.ScadaBridge.SiteRuntime/Actors/DeploymentManagerActor.cs

@@ -646,7 +646,7 @@ public class DeploymentManagerActor : ReceiveActor, IWithTimers
         for (var i = startIdx; i < endIdx; i++)
         {
             var config = state.Configs[i];
-            EnsureDclConnections(config.ConfigJson);
+            // CreateInstanceActor ensures this config's DCL connections (register row 85).
             CreateInstanceActor(config.InstanceUniqueName, config.ConfigJson, config.RevisionHash);
         }
 
@@ -1076,10 +1076,8 @@ public class DeploymentManagerActor : ReceiveActor, IWithTimers
     {
         var instanceName = command.InstanceUniqueName;
 
-        // Ensure DCL connections exist for any data-sourced attributes
-        EnsureDclConnections(command.FlattenedConfigurationJson);
-
-        // Create the Instance Actor immediately
+        // Create the Instance Actor immediately. CreateInstanceActor first ensures the DCL
+        // connections this config's data-sourced attributes subscribe through (register row 85).
         CreateInstanceActor(instanceName, command.FlattenedConfigurationJson, command.RevisionHash);
         if (!isRedeploy)
             _deployedInstanceNames.Add(instanceName);
@@ -2725,6 +2723,31 @@ public class DeploymentManagerActor : ReceiveActor, IWithTimers
     /// </param>
     internal void CreateInstanceActor(string instanceName, string configJson, string revisionHash)
     {
+        // Deferred register row 85 — an Instance Actor is useless without the DCL connection
+        // actors its data-sourced attributes subscribe through, so ensuring them belongs in the
+        // single creation funnel rather than at each caller.
+        //
+        // This used to be the caller's job, and only TWO of the four callers did it: the
+        // boot-time batch and ApplyDeployment. The two self-heal starts did not —
+        // StartStoredInstance (the shared row-67 ensure-started / row-78 sweep path) and
+        // HandleEnableResult. Both therefore created an instance whose every tag subscribe was
+        // answered "Unknown connection: X" by the DCL manager, forever, because nothing else on
+        // the node would ever create that connection actor:
+        //
+        //  - Row 85's live symptom (2026-08-16): a replication-seeded deployed_configurations row
+        //    is started by the row-78 sweep, but the connection actor is only ever created as a
+        //    side effect of a deploy or the boot load, so tag subscribes failed for 6+ minutes
+        //    until a second pair restart let the boot load create it.
+        //  - The same defect is reachable with no replication at all: the boot load reads only
+        //    ENABLED configs, so a node that boots with an instance DISABLED never creates that
+        //    instance's connections, and enabling it afterwards hit the identical dead end.
+        //
+        // Placed BEFORE the already-exists guard so the two paths that already called it keep
+        // their exact previous semantics (they called it unconditionally). It is cheap and
+        // silent when there is nothing to do: EnsureDclConnection is hash-guarded on
+        // _createdConnections, so an unchanged connection is a no-op with no message and no log.
+        EnsureDclConnections(configJson);
+
         if (_instanceActors.ContainsKey(instanceName))
         {
             _logger.LogWarning("Instance Actor {Instance} already exists, skipping creation", instanceName);