feat: real-time sync, notification & social system overhaul

- Add WS events: dm_channel_created, dm_channel_closed, friend_removed,
  channel_created/updated/deleted, server_updated
- Fix first-ever DM: broadcast dm_channel_created to recipient
- Add DELETE /api/dm/:id for closing DMs with re-open support
- Wire Close DM button in sidebar
- Fix dm_message_created for unknown channels (safety net)
- Broadcast friend_removed on friend deletion
- Sound system: track realtimeMessageEvents separately from API loads,
  play notification for messages in all channels, not just current
- Optimistic updates: send/edit/delete messages appear instantly with
  rollback on failure, temp message deduplication on WS echo
- Channel CRUD broadcasts to all server members
- Server update broadcast on PATCH
- Server join registers user in connectionManager immediately
- Reconnect: only reload current channel, preserve other channel caches
- Activity panel, right panel, member list toggle components

packages/server/src/routes/servers.ts

@@ -275,7 +275,15 @@ export async function serverRoutes(app: FastifyInstance): Promise<void> {
       return reply.code(500).send({ error: 'Failed to update server', statusCode: 500 });
     }
 
-    return reply.code(200).send(rowToServer(updated));
+    const serverData = rowToServer(updated);
+
+    // Broadcast server_updated to all server members
+    connectionManager.sendToServer(id, {
+      type: 'server_updated',
+      server: serverData,
+    });
+
+    return reply.code(200).send(serverData);
   });
 
   // DELETE /api/servers/:id - Delete server (owner only)
@@ -363,6 +371,9 @@ export async function serverRoutes(app: FastifyInstance): Promise<void> {
       joinedAt: now,
     }).run();
 
+    // Register the user in connectionManager so they receive WS broadcasts for this server
+    connectionManager.addUserServer(request.userId, id);
+
     return reply.code(200).send(rowToServer(server));
   });
 
@@ -395,6 +406,9 @@ export async function serverRoutes(app: FastifyInstance): Promise<void> {
       joinedAt: now,
     }).run();
 
+    // Register the user in connectionManager so they receive WS broadcasts for this server
+    connectionManager.addUserServer(request.userId, server.id);
+
     return reply.code(200).send(rowToServer(server));
   });