Fix exit errors and add UI image placeholder to README

README.md

@@ -8,6 +8,11 @@ A simple, motivating training diary focused on Calisthenics and basic health met
 - **Progress Tracking:** Visual graphs for weight and waist trends.
 - **Motivation:** Streak tracking to keep you consistent.
 
+## Interface
+
+![Exercise Diary Interface](assets/screenshot.png)
+*(Note: Replace `assets/screenshot.png` with a real screenshot of the app)*
+
 ## Installation
 
 1.  **Clone the repository:**

ui/app.py

@@ -43,6 +43,14 @@ class ExerciseDiaryApp(ctk.CTk):
         # Default View
         self.show_dashboard()
         
+        # Handle closing
+        self.protocol("WM_DELETE_WINDOW", self.on_close)
+
+    def on_close(self):
+        self.withdraw()
+        self.quit()
+        self.destroy()
+
     def clear_main_frame(self):
         for widget in self.main_frame.winfo_children():
             widget.destroy()