fix(server): realtime handler (#15146)

#### PR Dependency Tree


* **PR #15146** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

## Release Notes

* **Refactor**
* Reworked real-time backend wiring to centralize workspace, comments,
and Copilot embedding handlers under a unified server setup.
* Updated Copilot embedding real-time handling to use context
configuration when publishing updates.
* **New Features**
* Added automatic startup validation to ensure all required real-time
request/topic handlers are registered (for applicable server flavors).
* **Bug Fixes**
* Workspace real-time access now determines team status from quota
state.
* Improved Copilot embedding progress publishing (including completion
events).
* **Tests**
* Expanded real-time registry completeness and Copilot embedding
provider coverage.
  * Added quota-state restoration coverage after clearing stale expiry.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/plugins/copilot/module-providers.ts

@@ -109,9 +109,13 @@ export const COPILOT_RUNTIME_PROVIDERS = [
   TurnPersistence,
 ];
 
+export const COPILOT_CONTEXT_REALTIME_PROVIDERS = [
+  CopilotEmbeddingRealtimeProvider,
+];
+
 export const COPILOT_CONTEXT_PROVIDERS = [
   CopilotContextResolver,
-  CopilotEmbeddingRealtimeProvider,
+  ...COPILOT_CONTEXT_REALTIME_PROVIDERS,
 ];
 
 export const COPILOT_TRANSCRIPT_REALTIME_PROVIDERS = [