refactor: remove voice/recording/media features from frontend + prune lockfiles

- Delete pages: (dashboard)/{recordings,voice,media}/ incl. view.tsx
- Delete components/{voice,media}, hooks/{use-voice,use-recordings,use-media},
  lib/audio/ (mic-transmit, pcm-player, wav), api/{voice,recordings,media},
  types/{voice,recording,media}, lib/hash.ts
- Cut nav tiles (Active Voice Stages, Voice Recording Archive) from dashboard,
  MiniPlayer from ambient-app, hooks/types barrel exports, WS voice/media events
- Re-home guilds + textChannels to messages oRPC router (DB-derived) so the
  messages page picker keeps working; guild-picker simplified to text-only
- Clean Channel/AppConfig types of voice remnants
- Delete infra/docker/recordings/ + 11 voice/recording/video spec docs
- pnpm install: prune direct voice deps from gateway + backend lockfiles
  (prism-media/opusscript remain only as transitive discord.js deps)

services/backend/src/modules/messages/messages.repository.ts

@@ -522,6 +522,44 @@ export class MessagesRepository {
       username: r.username ? String(r.username) : null,
     }));
   }
+
+  /**
+   * Distinct guilds present in the message archive (drives the guild picker).
+   */
+  async listGuilds(): Promise<
+    Array<{ id: string; name: string; icon: string | null }>
+  > {
+    const db = getDatabase();
+    const rows = await db
+      .selectDistinct({ guild_id: pgMessagesTable.guild_id })
+      .from(pgMessagesTable)
+      .orderBy(pgMessagesTable.guild_id);
+    return rows.map((row) => ({
+      id: String(row.guild_id ?? ""),
+      name: `Guild ${String(row.guild_id).slice(0, 8)}`,
+      icon: null,
+    }));
+  }
+
+  /**
+   * Text channels for a guild, derived from the message archive
+   * (drives the channel picker).
+   */
+  async listTextChannels(
+    guildId: string,
+  ): Promise<Array<{ id: string; name: string; type: "text" }>> {
+    const db = getDatabase();
+    const rows = await db
+      .selectDistinct({ channel_id: pgMessagesTable.channel_id })
+      .from(pgMessagesTable)
+      .where(eq(pgMessagesTable.guild_id, guildId))
+      .orderBy(pgMessagesTable.channel_id);
+    return rows.map((row) => ({
+      id: String(row.channel_id ?? ""),
+      name: `Channel ${String(row.channel_id).slice(0, 8)}`,
+      type: "text" as const,
+    }));
+  }
 }
 
 export const messagesRepository = new MessagesRepository();

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

@@ -119,6 +119,16 @@ export class MessagesService {
     logger.debug({ limit, channelId }, "Getting recent message edits");
     return messagesRepository.getRecentEdits(limit, channelId);
   }
+
+  /** Distinct guilds present in the message archive (guild picker). */
+  async getGuilds() {
+    return messagesRepository.listGuilds();
+  }
+
+  /** Text channels for a guild (channel picker). */
+  async getTextChannels(guildId: string) {
+    return messagesRepository.listTextChannels(guildId);
+  }
 }
 
 /** Shape returned to the frontend (text + rich metadata from the archive payload). */