feat: compact boundary divider, overlay fix, approval window, PiP, Tauri enhancements

- Add CompactBoundaryDivider component for compact_boundary system messages
- Fix readability overlay: v-if removes element entirely at 0% opacity
- Add approval page and window composable
- Add PiP window support and loading screen
- Tauri: add window management commands and capabilities
- Disable Ctrl+1..5 shortcuts in Tauri (handled by global shortcuts)

package.json

@@ -10,7 +10,7 @@
     "start:frontend": "cd frontend && bun run dev --host",
     "tauri": "npx --prefix frontend tauri",
     "tauri:dev": "npx --prefix frontend tauri dev",
-    "tauri:build": "npx --prefix frontend tauri build",
+    "tauri:build": "frontend/node_modules/.bin/tauri build",
     "tauri:android:init": "npx --prefix frontend tauri android init",
     "tauri:android:build": "npx --prefix frontend tauri android build",
     "build:android:tauri": "cd src-tauri/gen/android && ./gradlew assembleRelease -x rustBuildArm64Release -x rustBuildArmRelease -x rustBuildX86Release -x rustBuildX86_64Release",