fix: move closure + MutexGuard Send dans la boucle de monitoring

- setup: move |app| pour ownership de config
- monitoring loop: MutexGuard droppé dans un bloc avant wait_for_backend().await

desktop/src/main.rs

@@ -391,7 +391,7 @@ fn main() {
             save_window_state,
             get_window_state,
         ])
-        .setup(|app| {
+        .setup(move |app| {
             // Restore window position/size
             if let Some(window) = app.get_webview_window("main") {
                 if let (Some(x), Some(y)) = (config.window_x, config.window_y) {
@@ -437,20 +437,20 @@ fn main() {
                     tokio::time::sleep(Duration::from_secs(5)).await;
 
                     let state = handle2.state::<BackendProcess>();
-                    let mut child_guard = match state.child.lock() {
-                        Ok(g) => g,
-                        Err(_) => break,
+                    // Drop guard before any await
+                    let died = {
+                        let mut child_guard = match state.child.lock() {
+                            Ok(g) => g,
+                            Err(_) => break,
+                        };
+                        match &mut *child_guard {
+                            Some(child) => child.try_wait().ok().flatten().is_some(),
+                            None => true,
+                        }
                     };
 
-                    let died = match &mut *child_guard {
-                        Some(child) => child.try_wait().ok().flatten().is_some(),
-                        None => true,
-                    };
-                    drop(child_guard);
-
                     if died {
                         warn!("Backend process died unexpectedly!");
-                        // Inject a notice into the UI
                         if let Some(window) = handle2.get_webview_window("main") {
                             let _ = window.eval(
                                 r#"if (typeof showBackendCrashBanner === 'function') showBackendCrashBanner();"#,
@@ -458,7 +458,7 @@ fn main() {
                         }
                     }
 
-                    // If we were restarting, check if new backend is ready
+                    // If restarting, check if new backend is ready
                     let restarting = state.restarting.lock().ok().map(|r| *r).unwrap_or(false);
                     if restarting {
                         if wait_for_backend().await.is_ok() {