feat: add i18n, platform channels page, and WeChat QR login

- Add vue-i18n with auto-detect browser language and manual toggle (EN/中文)
- Move platform channels to separate page with credential management
- Support Telegram, Discord, Slack, WhatsApp, Matrix, Feishu, Weixin, WeCom
- Add WeChat QR code login (opens in browser, polls status, auto-saves)
- Write platform credentials to ~/.hermes/.env matching hermes gateway setup
- Auto restart gateway after platform config changes
- Add settings store with per-section save for all config categories
- Persist session group collapse state across navigation
- Fix pre-existing TypeScript build errors

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/main.ts

@@ -1,10 +1,12 @@
 import { createApp } from 'vue'
 import { createPinia } from 'pinia'
 import router from './router'
+import { i18n } from './i18n'
 import App from './App.vue'
 import './styles/global.scss'
 
 const app = createApp(App)
 app.use(createPinia())
+app.use(i18n)
 app.use(router)
 app.mount('#app')