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/osd/__init__.py

@@ -0,0 +1,8 @@
+from .main import OSDWindow  # noqa: F401
+from .components import (  # noqa: F401
+    AudioOSDContainer,
+    BrightnessOSDContainer,
+    MicrophoneOSDContainer,
+    CapsLockOSDContainer,
+    KeyboardLayoutOSDContainer,
+)