feat(app-tauri): fermeture des fenêtres auxiliaires quand la principale se ferme (#39)

Ajoute close_non_main_webview_windows sur l'event de fermeture de la
fenêtre principale, avec le prédicat should_close_with_main_window qui
exclut la fenêtre "main" et cible toutes les fenêtres auxiliaires
(vues détachées, settings…). Couvert par 3 tests unitaires.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

crates/app-tauri/src/lib.rs

@@ -124,6 +124,8 @@ pub fn run() {
                                 let _ = model_servers.stop_on_app_exit().await;
                             });
                         }
+
+                        close_non_main_webview_windows(&handle);
                     }
                 });
             }
@@ -253,3 +255,39 @@ pub fn run() {
         .run(tauri::generate_context!())
         .expect("error while running IdeA Tauri application");
 }
+
+fn close_non_main_webview_windows(handle: &tauri::AppHandle) {
+    for (label, window) in handle.webview_windows() {
+        if !should_close_with_main_window(&label) {
+            continue;
+        }
+
+        let _ = window.close();
+    }
+}
+
+fn should_close_with_main_window(label: &str) -> bool {
+    label != "main"
+}
+
+#[cfg(test)]
+mod tests {
+    use super::should_close_with_main_window;
+
+    #[test]
+    fn main_window_close_does_not_target_main_again() {
+        assert!(!should_close_with_main_window("main"));
+    }
+
+    #[test]
+    fn main_window_close_targets_detached_view_windows() {
+        assert!(should_close_with_main_window(
+            "view-work-00000000-0000-0000-0000-000000000001"
+        ));
+    }
+
+    #[test]
+    fn main_window_close_targets_other_auxiliary_windows() {
+        assert!(should_close_with_main_window("settings"));
+    }
+}