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/whisperSocket.ts

@@ -4,7 +4,8 @@
  */
 
 import { ref } from 'vue'
-import { endpoints } from '../config/endpoints'
+import { resolveEndpoints } from '../config/endpoints'
+import { apiFetch } from '@/lib/tauri'
 
 export type WhisperStatus = 'offline' | 'loading' | 'ready'
 
@@ -28,8 +29,8 @@ const listeners = new Set<TranscriptionCallback>()
 function connect() {
   if (socket?.readyState === WebSocket.OPEN || socket?.readyState === WebSocket.CONNECTING) return
 
-  console.log('[WhisperSocket] Connecting to', endpoints.whisper)
-  socket = new WebSocket(endpoints.whisper)
+  console.log('[WhisperSocket] Connecting to', resolveEndpoints().whisper)
+  socket = new WebSocket(resolveEndpoints().whisper)
 
   const timeout = setTimeout(() => {
     if (socket && socket.readyState !== WebSocket.OPEN) {
@@ -86,7 +87,7 @@ function scheduleReconnect() {
 
 async function checkStatusAndConnect() {
   try {
-    const res = await fetch('/api/whisper/status')
+    const res = await apiFetch('/api/whisper/status')
     const data = await res.json()
     if (data.running) {
       connect()
@@ -148,7 +149,7 @@ export async function reconnect() {
   }
 
   try {
-    const res = await fetch('/api/whisper/toggle', { method: 'POST' })
+    const res = await apiFetch('/api/whisper/toggle', { method: 'POST' })
     const data = await res.json()
     if (data.running) {
       connect()
@@ -158,7 +159,7 @@ export async function reconnect() {
         for (let i = 0; i < 60; i++) {
           await new Promise(r => setTimeout(r, 2000))
           try {
-            const s = await fetch('/api/whisper/status')
+            const s = await apiFetch('/api/whisper/status')
             const d = await s.json()
             if (d.running) {
               connect()