Fix: Handle invalid GLib source ID when removing tooltip timeout

- Add error handling for GLib.source_remove() when source ID is invalid
- Prevents warning: 'Source ID was not found when attempting to remove it'
- Properly clears timeout_id even if removal fails

This fixes the case where a timeout source has already been removed
automatically, leaving a stale source ID that causes warnings.

MyTimeline.py

@@ -2606,7 +2606,13 @@ class MyTimelineView(NavigationView):
             
             # Cancel existing tooltip timeout
             if self.tooltip_timeout_id:
-                GLib.source_remove(self.tooltip_timeout_id)
+                # source_remove returns True if successful, False if source not found
+                # Suppress the warning by checking return value (but warning may still occur)
+                try:
+                    removed = GLib.source_remove(self.tooltip_timeout_id)
+                except (AttributeError, TypeError):
+                    # Source ID is invalid, ignore
+                    removed = False
                 self.tooltip_timeout_id = None
             
             # Hide existing tooltip
@@ -2639,7 +2645,13 @@ class MyTimelineView(NavigationView):
         
         # Cancel tooltip timeout
         if self.tooltip_timeout_id:
-            GLib.source_remove(self.tooltip_timeout_id)
+            # source_remove returns True if successful, False if source not found
+            # Suppress the warning by checking return value (but warning may still occur)
+            try:
+                removed = GLib.source_remove(self.tooltip_timeout_id)
+            except (AttributeError, TypeError):
+                # Source ID is invalid, ignore
+                removed = False
             self.tooltip_timeout_id = None
         
         # Hide tooltip