fix(server): close leaked redis sockets so e2e jest exits (#252)

The full-AppModule e2e (apps/server/test/app.e2e-spec.ts) passed but jest
never exited, burning CI to its timeout. Diagnosis (process._getActiveHandles
after app.close()) showed exactly two ioredis sockets to :6379 still open after
shutdown; everything else (BullMQ queues/workers, @nestjs/schedule intervals,
nestjs-ioredis, nestjs-kysely pg pool, @nestjs/cache-manager Keyv store,
hocuspocus pub/sub) already closes on app.close().

The two leaks were owned-but-never-closed clients:

1. ThrottleModule passed a pre-built `new Redis(...)` instance to
   ThrottlerStorageRedisService. With an instance, the lib sets
   disconnectRequired=false, so its onModuleDestroy never disconnects.
   Pass ioredis options instead so the service owns + disconnects the client.

2. CollaborationGateway created a source `new RedisClient(...)` that
   RedisSyncExtension only duplicates into pub/sub; the extension's onDestroy
   disconnects those duplicates but not the source. Keep a reference and
   disconnect it after the hocuspocus onDestroy hook in destroy().

Both are real lifecycle fixes (production shutdown is now clean too), so no
--forceExit is needed. Verified against real Postgres+Redis:
  - test:e2e (no forceExit, --runInBand) exits 0 in ~18s (was: hung forever)
  - --detectOpenHandles exits 0 with no open-handle report
  - active handles after app.close(): none
CI timeout-minutes safety nets left untouched.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/server/src/integrations/throttle/throttle.module.ts

@@ -10,7 +10,6 @@ import {
   PAGE_TEMPLATE_THROTTLER,
   PUBLIC_SHARE_AI_THROTTLER,
 } from './throttler-names';
-import Redis from 'ioredis';
 
 @Module({
   imports: [
@@ -32,16 +31,18 @@ import Redis from 'ioredis';
             { name: PUBLIC_SHARE_AI_THROTTLER, ttl: 60_000, limit: 5 },
           ],
           errorMessage: 'Too many requests',
-          storage: new ThrottlerStorageRedisService(
-            new Redis({
-              host: redisConfig.host,
-              port: redisConfig.port,
-              password: redisConfig.password,
-              db: redisConfig.db,
-              family: redisConfig.family,
-              keyPrefix: 'throttle:',
-            }),
-          ),
+          // Pass ioredis options (not a pre-built Redis instance) so
+          // ThrottlerStorageRedisService owns the connection and disconnects it
+          // in its onModuleDestroy. Passing an instance leaves disconnectRequired
+          // false, so the socket would leak on shutdown (e2e jest never exits).
+          storage: new ThrottlerStorageRedisService({
+            host: redisConfig.host,
+            port: redisConfig.port,
+            password: redisConfig.password,
+            db: redisConfig.db,
+            family: redisConfig.family,
+            keyPrefix: 'throttle:',
+          }),
         };
       },
       inject: [EnvironmentService],