feat(reconcile): site-reconcile messages + expected-set/stage-if-absent repo

- Commons: ReconcileSiteRequest / ReconcileSiteResponse / ReconcileGapItem
  message contracts (site→central ClusterClient on startup; central reply with
  gap fetch tokens + orphan list + base URL).
- Commons: ExpectedDeployment projection record (Commons/Types/Deployment/),
  lightweight join of DeployedConfigSnapshot + Instance (no ConfigJson).
- IDeploymentManagerRepository: GetExpectedDeploymentsForSiteAsync (inner-join
  query returning deployed set for a site, excluding snapshot-less instances) +
  StagePendingIfAbsentAsync (insert-if-absent, self-contained save, returns bool;
  does NOT supersede — an existing pending row signals in-flight delivery).
- DeploymentManagerRepository: implement both methods; StagePendingIfAbsent
  commits internally (matches PurgeExpiredPendingDeployments convention).
- ReconcileRepositoryTests: 4 tests covering expected-set filter/IsEnabled/
  cross-site isolation, empty-site, stage-absent (true + row retrievable),
  stage-present (false + existing row unchanged); all pass.

src/ZB.MOM.WW.ScadaBridge.Commons/Messages/Deployment/ReconcileSiteRequest.cs

@@ -0,0 +1,11 @@
+namespace ZB.MOM.WW.ScadaBridge.Commons.Messages.Deployment;
+
+/// <summary>
+/// Site→central (over ClusterClient) on node startup: the node's local deployed inventory,
+/// so central can reply with fetch tokens for whatever the node is missing or stale
+/// (self-heal a node that was down during a deploy).
+/// </summary>
+public record ReconcileSiteRequest(
+    string SiteIdentifier,
+    string NodeId,
+    IReadOnlyDictionary<string, string> LocalNameToRevisionHash);

src/ZB.MOM.WW.ScadaBridge.Commons/Messages/Deployment/ReconcileSiteResponse.cs

@@ -0,0 +1,21 @@
+namespace ZB.MOM.WW.ScadaBridge.Commons.Messages.Deployment;
+
+/// <summary>
+/// Central→site reply: fresh fetch tokens for the gap (instances the node is missing or has at
+/// a stale revision), orphan names to log (present locally but no longer deployed centrally),
+/// and the base URL to fetch from.
+/// </summary>
+public record ReconcileSiteResponse(
+    IReadOnlyList<ReconcileGapItem> Gap,
+    IReadOnlyList<string> OrphanNames,
+    string CentralFetchBaseUrl);
+
+/// <summary>
+/// One instance the node must (re)fetch, with a freshly-minted short-TTL token.
+/// </summary>
+public record ReconcileGapItem(
+    string InstanceUniqueName,
+    string DeploymentId,
+    string RevisionHash,
+    bool IsEnabled,
+    string FetchToken);