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/main.py

@@ -0,0 +1,83 @@
+from fabric.widgets.box import Box
+from fabric.widgets.revealer import Revealer
+from fabric.widgets.wayland import WaylandWindow as Window
+from .components import (
+    AudioOSDContainer,
+    BrightnessOSDContainer,
+    MicrophoneOSDContainer,
+    CapsLockOSDContainer,
+    KeyboardLayoutOSDContainer,
+)
+
+
+class OSD(Box):
+    def __init__(self, window: Window, **kwargs):
+        super().__init__(name="osd", **kwargs)
+        self.window = window
+
+        self.revealer = Revealer(
+            transition_type="slide-up",
+            transition_duration=100,
+            child_revealed=False,
+        )
+        self.children = [self.revealer]
+
+        self.containers = {
+            "audio": AudioOSDContainer(window),
+            "brightness": BrightnessOSDContainer(window),
+            "microphone": MicrophoneOSDContainer(window),
+            "capslock": CapsLockOSDContainer(window),
+            "kb_layout": KeyboardLayoutOSDContainer(window),
+        }
+
+        # Set the OSD reference in containers
+        for container in self.containers.values():
+            container.osd = self
+
+        self.current_container = None
+
+    def show_container(self, container):
+        if self.current_container != container:
+            self.revealer.children = [container]
+            self.current_container = container
+        self.revealer.set_reveal_child(True)
+
+    def show_audio_osd(self):
+        self.show_container(self.containers.get("audio"))
+
+    def show_brightness_osd(self):
+        self.show_container(self.containers.get("brightness"))
+
+    def show_microphone_osd(self):
+        self.show_container(self.containers.get("microphone"))
+
+    def show_capslock_osd(self):
+        self.show_container(self.containers.get("capslock"))
+
+    def show_kb_layout_osd(self):
+        self.show_container(self.containers.get("kb_layout"))
+
+
+class OSDWindow(Window):
+    def __init__(self, **kwargs):
+        super().__init__(
+            name="osd-window",
+            title="modus-osd",
+            anchor="bottom",
+            margin="0px 0px 40px 0px",
+            visible=False,
+            all_visible=False,
+            pass_through=True,
+            layer="overlay",
+            **kwargs,
+        )
+        self.osd = OSD(window=self)
+        self.add(self.osd)
+
+
+if __name__ == "__main__":
+    from fabric import Application
+
+    osd_window = OSDWindow()
+    app = Application("modus-osd", osd_window)
+    app.run()