feat: bind/unbind by id, video streaming proxy, unmute default, library refresh, hamburger click-outside

- Core API: bind/unbind accept id (integer PK) when face_id is null
- Tauri proxy: stream video responses instead of buffering for seek bar
- VideoPlayer: remove muted attribute, unmute by default
- LibraryView: call invalidateFiles() before ensureFiles() on register/unregister
- PeopleView: close sort panel on click-outside, not just hamburger toggle
- bind_face: prefer face_id, fallback to id when face_id is null

src/main.ts

@@ -1,7 +1,9 @@
 import { createApp } from 'vue'
 import App from './App.vue'
 import router from './router'
+import vObserve from './directives/vObserve'
 
 const app = createApp(App)
 app.use(router)
+app.directive('observe', vObserve)
 app.mount('#app')