feat(sitecallaudit): PullSiteCalls reconciliation plumbing (store read + RPC + site handler + central client)

Site Call Audit (#22): build the documented periodic reconciliation PULL
self-heal path for the eventually-consistent central SiteCalls mirror, as a
dedicated PullSiteCalls gRPC RPC kept separate from the audit pull. This is the
pull PLUMBING only; the central reconciliation tick is a separate follow-up.

- IOperationTrackingStore.ReadChangedSinceAsync(sinceUtc, batchSize): inclusive
  UpdatedAtUtc cursor, oldest-first, batch-capped; SQLite impl projects tracking
  rows onto SiteCallOperational (Kind->Channel, TargetSummary->Target, SourceSite
  left empty - the store has no site-id column).
- sitestream.proto: rpc PullSiteCalls + PullSiteCallsRequest/Response, mirroring
  PullAuditEvents; regenerated checked-in SiteStreamGrpc/*.cs.
- SiteCallDtoMapper.ToDto(SiteCallOperational): inverse of FromDto for the handler.
- SiteStreamGrpcServer.PullSiteCalls handler + SetOperationTrackingStore seam;
  Host wires the seam alongside SetSiteAuditQueue (site roles only).
- Central IPullSiteCallsClient + GrpcPullSiteCallsClient (home: AuditLog/Central to
  reuse ISiteEnumerator; SiteCallAudit does not reference AuditLog). Re-stamps
  SourceSite from the dialed siteId; no-throw on tolerable transport faults;
  SpecifyKind (not ToUniversalTime) cursor handling. Central-only DI registration.

Tests: ReadChangedSinceAsync (4), PullSiteCalls handler (6), GrpcPullSiteCallsClient
(8). Full solution build 0 warnings/0 errors (TreatWarningsAsErrors).

src/ZB.MOM.WW.ScadaBridge.Commons/Messages/Integration/PullSiteCallsResponse.cs

@@ -0,0 +1,17 @@
+using ZB.MOM.WW.ScadaBridge.Commons.Entities.Audit;
+
+namespace ZB.MOM.WW.ScadaBridge.Commons.Messages.Integration;
+
+/// <summary>
+/// Site Call Audit (#22) periodic reconciliation pull response: the next batch of
+/// site cached-call operational rows (the eventually-consistent <c>SiteCalls</c>
+/// mirror's self-heal feed) plus a <paramref name="MoreAvailable"/> flag signalling
+/// the caller to advance the watermark and pull again. Mirrors
+/// <see cref="PullAuditEventsResponse"/>; carries the central <see cref="SiteCall"/>
+/// entity the ingest path upserts. See Component-SiteCallAudit.md.
+/// </summary>
+/// <param name="SiteCalls">The next batch of operational rows, ordered oldest-first by <see cref="SiteCall.UpdatedAtUtc"/>.</param>
+/// <param name="MoreAvailable">True when the site saturated the requested batch size — the caller should advance the cursor and pull again.</param>
+public sealed record PullSiteCallsResponse(
+    IReadOnlyList<SiteCall> SiteCalls,
+    bool MoreAvailable);