feat(server): hot-reload config store and reloadable infra clients

- Replace single Load() with a watching Store that re-reads config files
  (and config.local.yaml) and fans out a ReloadEvent with a per-field diff
  so consumers can decide whether the change is hot-applicable or requires
  a process restart.
- Wrap llm, retrieval, vector store, and object storage clients in
  Reloadable* shells so the bootstrap can swap their underlying impls when
  config changes without re-instantiating handlers.
- Make jwt.Manager and ops TokenIssuer mutable under a lock so secrets and
  TTLs can be rotated live; thread default plan code through a setter on
  the ops AdminUserService.
- Wire ConfigStore through bootstrap and every cmd/main.go, scheduler /
  worker / tenant-api / ops-api start the watcher; services and handlers
  take a config.Provider so they always read current values for things
  like generation.stream_enabled, scheduler dispatch, retrieval, etc.
- Switch shared/config decoding off viper to a Kratos-derived runtime
  package so env placeholders (\${VAR:default}) resolve consistently and
  the same source machinery powers both the loader and the watcher.

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

server/cmd/tenant-api/main.go

@@ -28,22 +28,24 @@ func main() {
 	workerCtx, workerCancel := context.WithCancel(context.Background())
 	defer workerCancel()
 
+	app.StartConfigWatcher(workerCtx)
+
 	app.GenerationStreams.Run(workerCtx)
 	app.DesktopTaskStreams.Run(workerCtx)
 	app.DesktopDispatch.Run(workerCtx)
 
-	monitoringService := tenantapp.NewMonitoringService(app.DB, app.MonitoringDB, app.RabbitMQ, app.Config.MonitoringDispatch, app.Config.BrandLibrary, app.Logger).WithRedis(app.Redis)
+	monitoringService := app.MonitoringService
 	monitoringCallbackService := tenantapp.NewMonitoringCallbackService(app.DB, app.MonitoringDB, app.RabbitMQ, app.LLM, app.Logger)
 	tenantapp.NewMonitoringCollectOutboxWorker(monitoringService, app.Logger).Start(workerCtx)
-	tenantapp.NewMonitoringResultIngestWorker(monitoringCallbackService, app.RabbitMQ, app.Logger, app.Config.MonitoringWorkers).Start(workerCtx)
-	tenantapp.NewMonitoringProjectionRebuildWorker(monitoringCallbackService, app.RabbitMQ, app.Logger, app.Config.MonitoringWorkers).Start(workerCtx)
+	tenantapp.NewMonitoringResultIngestWorker(monitoringCallbackService, app.RabbitMQ, app.Logger, app.Config().MonitoringWorkers).Start(workerCtx)
+	tenantapp.NewMonitoringProjectionRebuildWorker(monitoringCallbackService, app.RabbitMQ, app.Logger, app.Config().MonitoringWorkers).Start(workerCtx)
 	tenantapp.NewDesktopAccountHealthSinkWorker(app.DB, app.RabbitMQ, app.Logger).Start(workerCtx)
 	imageService := tenantapp.NewImageService(app.DB, app.ObjectStorage, app.RabbitMQ, app.Logger)
 	tenantapp.NewImageAssetWorker(imageService, app.RabbitMQ, app.Logger).Start(workerCtx)
 
 	transport.RegisterRoutes(app)
 
-	addr := fmt.Sprintf(":%d", app.Config.Server.Port)
+	addr := fmt.Sprintf(":%d", app.Config().Server.Port)
 	app.Logger.Sugar().Infof("tenant-api starting on %s", addr)
 
 	go func() {