feat(server): entitlement based model (#14996)

#### PR Dependency Tree


* **PR #14996** 👈

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## Summary by CodeRabbit

* **New Features**
  * Admin mutations to grant/revoke commercial entitlements.
  * New Doc comment-update permission.
  * Realtime user/workspace quota-state endpoints and live-update rooms.

* **Bug Fixes**
  * More accurate readable-doc filtering and permission evaluation.

* **Refactor**
* Workspace feature management moved to entitlement-based model;
permission and quota pipelines redesigned.
  * Admin workspace UI now edits flags only (feature toggles removed).

* **Tests**
* Extensive new and updated tests for permissions, entitlements, quota,
projection, and backfills.

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packages/backend/server/src/core/sync/gateway.ts

@@ -41,8 +41,8 @@ import {
 } from '../doc';
 import { applyUpdatesWithNative } from '../doc/merge-updates';
 import {
-  AccessController,
   type DocAction,
+  PermissionAccess,
   WorkspaceAction,
 } from '../permission';
 import { DocID } from '../utils/doc';
@@ -223,7 +223,7 @@ export class SpaceSyncGateway
   private activeUsersFlushQueued = false;
 
   constructor(
-    private readonly ac: AccessController,
+    private readonly ac: PermissionAccess,
     private readonly event: EventBus,
     private readonly workspace: PgWorkspaceDocStorageAdapter,
     private readonly userspace: PgUserspaceDocStorageAdapter,
@@ -899,7 +899,7 @@ class WorkspaceSyncAdapter extends SyncSocketAdapter {
   constructor(
     client: Socket,
     storage: DocStorageAdapter,
-    private readonly ac: AccessController,
+    private readonly ac: PermissionAccess,
     private readonly docReader: DocReader,
     private readonly models: Models
   ) {