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/src-tauri/Cargo.toml

@@ -26,6 +26,7 @@ tauri-plugin-updater = "2.9.0"
 tauri-plugin-process = "2.3.0"
 tauri-plugin-notification = "2"
 tauri-plugin-deep-link = "2"
+tauri-plugin-single-instance = "2"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 sysinfo = { version = "0.31", default-features = false, features = ["multithread", "network", "system", "disk"] }
@@ -41,6 +42,7 @@ hostname = "0.4"
 base64 = "0.22"
 sha2 = "0.10"
 convex = "0.10.2"
+uuid = { version = "1", features = ["v4"] }
 # SSE usa reqwest com stream, nao precisa de websocket
 
 [target.'cfg(windows)'.dependencies]