feat(scheduler,packsregistry,registry): postgres backend cutover

Sprint SPRINT_20260415_003_DOCS_scheduler_registry_real_backend_cutover.

- Scheduler WebService: Postgres-backed audit service + resolver job service,
  system schedule bootstrap, durable host tests, jwt app factory
- PacksRegistry: persistence extensions + migration 002 runtime pack repo,
  durable runtime + startup contract tests
- Registry.TokenService: Postgres plan rule store + admin endpoints,
  migration 001 initial schema, durable runtime + persistence tests
- Scheduler.Plugin.Doctor: wiring for doctor job plugin
- Sprint _019 (webhook rate limiter) and _002 (compose storage compat)
  land separately.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/Registry/StellaOps.Registry.TokenService/Admin/PlanAdminEndpoints.cs

@@ -250,11 +250,12 @@ public static class PlanAdminEndpoints
         page = Math.Max(1, page);
 
         var entries = await store.GetAuditHistoryAsync(planId, page, pageSize, cancellationToken);
+        var totalCount = await store.GetAuditHistoryCountAsync(planId, cancellationToken);
 
         var response = new PaginatedResponse<PlanAuditEntry>
         {
             Items = entries,
-            TotalCount = entries.Count, // Note: in-memory store doesn't track total; real store should
+            TotalCount = totalCount,
             Page = page,
             PageSize = pageSize,
         };