feat(desktop): adiciona Raven Service e corrige UAC

- Implementa Windows Service (raven-service) para operacoes privilegiadas
- Comunicacao via Named Pipes sem necessidade de UAC adicional
- Adiciona single-instance para evitar multiplos icones na bandeja
- Corrige todos os warnings do clippy (rustdesk, lib, usb_control, agent)
- Remove fallback de elevacao para evitar UAC desnecessario
- USB Policy e RustDesk provisioning agora usam o servico quando disponivel

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/desktop/package.json

@@ -8,7 +8,9 @@
     "build": "tsc && vite build",
     "preview": "vite preview",
     "tauri": "node ./scripts/tauri-with-stub.mjs",
-    "gen:icon": "node ./scripts/build-icon.mjs"
+    "gen:icon": "node ./scripts/build-icon.mjs",
+    "build:service": "cd service && cargo build --release",
+    "build:all": "bun run build:service && bun run tauri build"
   },
   "dependencies": {
     "@radix-ui/react-scroll-area": "^1.2.3",