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/components/ui/SwUpdatePrompt.tsx

@@ -0,0 +1,22 @@
+import { useRegisterSW } from 'virtual:pwa-register/react';
+
+export function SwUpdatePrompt() {
+  const {
+    needRefresh: [needRefresh],
+    updateServiceWorker,
+  } = useRegisterSW();
+
+  if (!needRefresh) return null;
+
+  return (
+    <div className="fixed bottom-6 left-1/2 -translate-x-1/2 z-[9999] glass-pill px-4 py-2.5 flex items-center gap-3 text-sm text-txt-primary shadow-lg">
+      <span>A new version is available</span>
+      <button
+        onClick={() => updateServiceWorker(true)}
+        className="px-3 py-1 rounded-md bg-accent-primary text-white text-xs font-medium hover:opacity-90 transition-opacity"
+      >
+        Reload
+      </button>
+    </div>
+  );
+}