fix(window): hide chat window on close instead of destroying it

Intercept WindowEvent::CloseRequested on the 'chat' window and call
window.hide() + api.prevent_close(). Without this, clicking the X
destroys the window — get_webview_window("chat") then returns None
and subsequent tray clicks do nothing.

src-tauri/src/lib.rs

@@ -76,6 +76,20 @@ pub fn run() {
                 .map(|pf| pf.log_paths.clone())
                 .unwrap_or_default();
 
+            // Intercept the chat window's close button so it hides rather than
+            // destroys the window. Without this, closing once makes the window
+            // unreachable — get_webview_window("chat") returns None and the tray
+            // click does nothing.
+            if let Some(chat_win) = app.get_webview_window("chat") {
+                let win = chat_win.clone();
+                chat_win.on_window_event(move |event| {
+                    if let tauri::WindowEvent::CloseRequested { api, .. } = event {
+                        let _ = win.hide();
+                        api.prevent_close();
+                    }
+                });
+            }
+
             let rx = watcher::spawn(log_paths);
             let pf = Arc::new(pattern_file);
             let app_handle = app.handle().clone();