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/discord-gateway/src/modules/voice-recording/mediaSource.ts

@@ -307,7 +307,9 @@ export async function extractMediaInfo(url: string): Promise<MediaInfo> {
     if (proc.stderr) {
       proc.stderr.on("data", (chunk: Buffer) => {
         if (stderrBuf.length < MAX_STDERR) {
-          stderrBuf += chunk.toString("utf8").slice(0, MAX_STDERR - stderrBuf.length);
+          stderrBuf += chunk
+            .toString("utf8")
+            .slice(0, MAX_STDERR - stderrBuf.length);
         }
       });
     }

services/discord-gateway/src/modules/voice-recording/recorder.ts

@@ -194,29 +194,33 @@ export function stopRecording(guildId: string): void {
     const snapshot = session.snapshot(Date.now());
     const stoppedAt = Date.now();
 
-    _eventBroadcaster.voiceRecordingStopped({
-      guild_id: guildId,
-      session_id: session.sessionId,
-      duration_ms: snapshot.durationMs,
-      participants: snapshot.participants.length,
-      segment_count: snapshot.segments.length,
-      status: snapshot.status,
-      stopped_at: stoppedAt,
-    }).catch(() => {});
+    _eventBroadcaster
+      .voiceRecordingStopped({
+        guild_id: guildId,
+        session_id: session.sessionId,
+        duration_ms: snapshot.durationMs,
+        participants: snapshot.participants.length,
+        segment_count: snapshot.segments.length,
+        status: snapshot.status,
+        stopped_at: stoppedAt,
+      })
+      .catch(() => {});
 
     // Auto-enqueue muxer job if there are multiple segments
     const segments = snapshot.segments;
     if (segments.length >= 2) {
       const outputFile = `${config.RECORDINGS_DIR}/merged/${session.sessionId}.ogg`;
-      import("./muxer.js").then(({ enqueueMuxerJob }) => {
-        enqueueMuxerJob({
-          inputs: segments.map((s) => s.oggPath),
-          output: outputFile,
-          guildId,
-          channelId: snapshot.channelId,
-          sessionId: session.sessionId,
-        }).catch(() => {});
-      }).catch(() => {});
+      import("./muxer.js")
+        .then(({ enqueueMuxerJob }) => {
+          enqueueMuxerJob({
+            inputs: segments.map((s) => s.oggPath),
+            output: outputFile,
+            guildId,
+            channelId: snapshot.channelId,
+            sessionId: session.sessionId,
+          }).catch(() => {});
+        })
+        .catch(() => {});
     }
   }
 }

services/discord-gateway/src/modules/voice-recording/voiceController.ts

@@ -7,34 +7,49 @@ import { startRecording, stopRecording } from "./recorder.js";
 
 const logger = createChildLogger("voice-controller");
 
+// ─── Types ───────────────────────────────────────────────────────────────
+
+export interface GuildVoiceState {
+  guildId: string;
+  channelId: string;
+  channelName: string;
+  connectedAt: number;
+}
+
 export interface VoiceStatus {
   ready: boolean;
   connected: boolean;
   activeGuildId: string | null;
   activeChannelId: string | null;
   activeChannelName: string | null;
+  /** Multi-guild: list of all active connections */
+  connections: GuildVoiceState[];
 }
 
+// ─── VoiceController ─────────────────────────────────────────────────────
+
 export class VoiceController {
-  private activeGuildId: string | null = null;
-  private activeChannelId: string | null = null;
-  private activeChannelName: string | null = null;
-  private connecting = false;
+  private connections = new Map<string, GuildVoiceState>();
+  private connecting = new Set<string>();
 
   constructor(private readonly client: Client) {}
 
   getStatus(): VoiceStatus {
     logger.debug("getStatus called");
-    const connection = this.activeGuildId
-      ? getVoiceConnection(this.activeGuildId)
+
+    // Primary connection (legacy compat — first entry or explicitly set)
+    const primaryGuildId = this.connections.keys().next().value ?? null;
+    const primary = primaryGuildId
+      ? this.connections.get(primaryGuildId)
       : undefined;
 
     return {
       ready: this.client.isReady(),
-      connected: Boolean(connection),
-      activeGuildId: this.activeGuildId,
-      activeChannelId: this.activeChannelId,
-      activeChannelName: this.activeChannelName,
+      connected: this.connections.size > 0,
+      activeGuildId: primary?.guildId ?? null,
+      activeChannelId: primary?.channelId ?? null,
+      activeChannelName: primary?.channelName ?? null,
+      connections: Array.from(this.connections.values()),
     };
   }
 
@@ -48,18 +63,21 @@ export class VoiceController {
       );
     }
 
-    if (this.connecting) {
+    if (this.connecting.has(guildId)) {
       throw new AppError(
-        "Voice connection is already in progress",
+        `Voice connection for guild ${guildId} is already in progress`,
         "CONNECT_IN_PROGRESS",
         409,
       );
     }
 
-    this.connecting = true;
+    this.connecting.add(guildId);
 
     try {
-      await this.disconnect();
+      // Disconnect existing connection for this guild first
+      if (this.connections.has(guildId)) {
+        await this.disconnectGuild(guildId);
+      }
 
       const guild = this.getGuild(guildId);
       const channel =
@@ -94,10 +112,18 @@ export class VoiceController {
         );
       }
 
-      discordPlayer.setConnection(connection as VoiceConnection);
-      this.activeGuildId = guildId;
-      this.activeChannelId = channelId;
-      this.activeChannelName = channel.name;
+      // If this is the first connection, set it as the player's connection
+      if (this.connections.size === 0) {
+        discordPlayer.setConnection(connection as VoiceConnection);
+      }
+
+      const state: GuildVoiceState = {
+        guildId,
+        channelId,
+        channelName: channel.name,
+        connectedAt: Date.now(),
+      };
+      this.connections.set(guildId, state);
 
       logger.info(
         { guildId, channelId, channelName: channel.name },
@@ -106,24 +132,31 @@ export class VoiceController {
 
       return this.getStatus();
     } finally {
-      this.connecting = false;
+      this.connecting.delete(guildId);
     }
   }
 
   async disconnect(): Promise<VoiceStatus> {
     logger.info("disconnect called");
-    if (this.activeGuildId) {
-      stopRecording(this.activeGuildId);
+
+    // Disconnect all guilds
+    const guildIds = Array.from(this.connections.keys());
+    for (const gid of guildIds) {
+      await this.disconnectGuild(gid);
     }
 
     discordPlayer.stop();
-    this.activeGuildId = null;
-    this.activeChannelId = null;
-    this.activeChannelName = null;
-
     return this.getStatus();
   }
 
+  async disconnectGuild(guildId: string): Promise<void> {
+    logger.info({ guildId }, "disconnectGuild called");
+    if (this.connections.has(guildId)) {
+      stopRecording(guildId);
+      this.connections.delete(guildId);
+    }
+  }
+
   private getGuild(guildId: string): Guild {
     const guild = this.client.guilds.cache.get(guildId);