feat: integrate Tauri v2 with Android widget and voice assistant

- Add Tauri v2 shell (Cargo, tauri.conf.json, capabilities, plugins)
- Migrate all fetch() calls to apiFetch() for Tauri-aware HTTP
- Migrate WebSocket endpoints to resolveEndpoints() for dynamic URLs
- Add ServerConfigDialog for remote server URL configuration
- Add tauri.ts lib with isTauri detection, apiFetch wrapper, plugin helpers
- Add server-config Pinia store with persistence via plugin-store
- Conditional PWA (disabled in Tauri builds)
- Android: home screen transcript widget (last 5 messages, 30s refresh)
- Android: voice command / share activity (SpeechRecognizer + WebSocket)
- Android: signed release APK with auto-copy to installers/
- Remove stale frontend/src-tauri directory

frontend/src/services/session-state-ws.ts

@@ -1,4 +1,4 @@
-import { endpoints } from '@/config/endpoints'
+import { resolveEndpoints } from '@/config/endpoints'
 import { useSessionState } from '@/stores/session-state'
 
 let ws: WebSocket | null = null
@@ -10,7 +10,7 @@ function connect() {
   const store = useSessionState()
 
   // Connect to terminal server (4103) — same base as terminal WS
-  const url = endpoints.terminal
+  const url = resolveEndpoints().terminal
   console.log('[SessionStateWS] Connecting to', url)
 
   ws = new WebSocket(url)