refactor(modules): improve exception handling and simplify service usage

Enhancements
- Replace bare `except:` with `except Exception:` in multiple modules- Cast step calculation to `int` for consistent type
- Simplify `get_battery_icon_file` to return a string directly
- Use `get_todo_service()` instead of module-level `todo_service` throughout todo widget
- Remove unused `"zen": "zen-browser"` mapping entry

Bug Fixes
- Prevent bare exception swallowing by catching `Exception` explicitly
- Ensure proper cleanup of timer IDs and other resources
- Delete unused modules/osdd components

New Features
- None

modules/controlcenter/per_app_volume.py

@@ -114,7 +114,6 @@ class PerAppVolumeControl(Box):
             "visual studio code": "vscode",
             "telegram": "telegram-desktop",
             "pulse": "audio-card",
-            "zen": "zen-browser",
             "pipewire": "audio-card",
             "alsa": "audio-card",
             "sink": "audio-speakers",
@@ -323,7 +322,7 @@ class PerAppVolumeControl(Box):
             for connection in self._signal_connections:
                 try:
                     audio_service.disconnect(connection)
-                except:
+                except Exception:
                     pass
 
         self._signal_connections.clear()