feat(auth): add skip persistence context key for file watcher events

Introduce `WithSkipPersist` to disable persistence during Manager Update/Register calls, preventing write-back loops caused by redundant file writes. Add corresponding tests and integrate with existing file store and conductor logic.

sdk/cliproxy/service.go

@@ -124,6 +124,7 @@ func (s *Service) ensureAuthUpdateQueue(ctx context.Context) {
 }
 
 func (s *Service) consumeAuthUpdates(ctx context.Context) {
+	ctx = coreauth.WithSkipPersist(ctx)
 	for {
 		select {
 		case <-ctx.Done():