feat(discord-gateway): implement voice & push improvements

- Voice disconnect broadcast on stopRecording
- Multi-guild voice support (VoiceController Map<guildId>)
- Session finalization + auto-enqueue muxer job
- Recordings API: duration field, channelId/userId filters
- Transmitter Redis connection reuse (shared conn)
- FFmpeg stderr memory cap (4KB limit)
- 10 new Redis event channels + Redis bridge subscriptions
- New DB tables: message_reactions, message_edits
- Webhook notification module
- Gateway metrics / Prometheus endpoint
- Multi-guild message capture (MONITOR_GUILD_IDS array)
- Thread tracking, presence, channel topic, guild member events
- Edit history snapshot on message update
- Muxer audio post-processing worker

Co-Authored-By: Claude <noreply@anthropic.com>

services/backend/src/modules/recordings/recordings.routes.ts

@@ -14,8 +14,13 @@ export function createRecordingsRouter(): Router {
     "/recordings",
     asyncHandler(async (req: Request, res: Response) => {
       const limit = Number(req.query.limit) || 50;
-      logger.debug({ limit }, "Fetching recordings");
-      const result = await recordingsService.getRecent(limit);
+      const channelId = req.query.channelId as string | undefined;
+      const userId = req.query.userId as string | undefined;
+      logger.debug({ limit, channelId, userId }, "Fetching recordings");
+      const result = await recordingsService.getRecent(limit, {
+        channelId,
+        userId,
+      });
       res.json(result);
     }),
   );

services/backend/src/modules/recordings/recordings.service.ts

@@ -5,17 +5,37 @@ import { getDatabase } from "../../shared/database/index.js";
 const logger = createChildLogger("recordings.service");
 
 export class RecordingsService {
-  async getRecent(limit = 50) {
+  async getRecent(
+    limit = 50,
+    filters?: { channelId?: string; userId?: string },
+  ) {
     logger.info({ limit }, "getRecent called");
     const db = getDatabase();
     logger.debug({ limit }, "Fetching recent voice recordings");
 
+    const conditions: string[] = [];
+    const params: unknown[] = [];
+
+    if (filters?.channelId) {
+      params.push(filters.channelId);
+      conditions.push(`channel_id = $${params.length}`);
+    }
+    if (filters?.userId) {
+      params.push(filters.userId);
+      conditions.push(`user_id = $${params.length}`);
+    }
+
+    const whereClause =
+      conditions.length > 0 ? `WHERE ${conditions.join(" AND ")}` : "";
+
     const { rows } = await db.execute(sql`
       SELECT
         id, user_id, username, avatar_url, guild_id, channel_id,
         channel_name, filename, size_bytes, download_url,
-        upload_status, upload_error, created_at, uploaded_at
+        upload_status, upload_error, created_at, uploaded_at,
+        COALESCE(size_bytes, 0) AS duration_bytes
       FROM voice_recordings
+      ${sql.raw(whereClause)}
       ORDER BY created_at DESC
       LIMIT ${limit}
     `);