feat: launch readiness — PWA, API hardening, memory leak fixes, sticker removal

- Add PWA infrastructure: vite-plugin-pwa, manifest, service worker,
  SW update prompt component, placeholder icons, Apple meta tags
- Harden API client: 401 auto-logout, AbortController timeouts
  (30s standard, 120s uploads), onUnauthorized callback
- Fix memory leaks: clear voice user status on leave, clean up all
  Maps (channelToSpaceMap, permissions, etc.) on removeSpace
- Upgrade error boundary to Aether Drift design with Try Again button,
  collapsible stack trace, and componentDidCatch logging
- Configure desktop icon paths in electron-builder.yml
- Remove sticker feature (server routes, schema, types, UI components)
- Fix Docker build: use **/node_modules in .dockerignore to prevent
  COPY from clobbering pnpm-installed workspace dependencies
- Add vite-env.d.ts declarations for noise suppressor wasm imports
- Exclude test files from tsc build via tsconfig

packages/web/src/hooks/useWebSocket.ts

@@ -333,6 +333,7 @@ function handleEvent(origin: string, event: ServerEvent): void {
         addVoiceUser(event.channelId, event.userId);
       } else {
         removeVoiceUser(event.channelId, event.userId);
+        clearVoiceUserStatus(event.userId);
       }
       break;
 
@@ -755,20 +756,6 @@ function handleEvent(origin: string, event: ServerEvent): void {
       break;
     }
 
-    // ─── Sticker events (all origins) ────────────────────────────────────
-
-    case 'sticker_pack_created':
-    case 'sticker_pack_updated':
-    case 'sticker_pack_deleted':
-    case 'sticker_created':
-    case 'sticker_deleted': {
-      // Invalidate the sticker picker cache so next open fetches fresh data
-      import('../components/chat/StickerPicker').then(({ invalidateStickerCache }) => {
-        invalidateStickerCache();
-      });
-      break;
-    }
-
     case 'pong':
       break;