feat(root): implement dynamic todo list refresh and UI enhancements

This change adds a mechanism to refresh the todo list dynamically when the underlying service updates, improving UI responsiveness and user experience. It also updates documentation and removes deprecated files.

- New Features:
  - Added `_refresh_todos` method to rebuild the todo list when `get_todo_service().todos` changes.
  - Introduced `TodoListCapture` class for mouse capture handling of the todo list window.
- Enhancements:
  - Updated README with corrected image paths, installation tips, and manual installation commands.
  - Introduced `start.py` to launch the application or lock mode.
  - Removed deprecated `config.json` and `debug_memory.py`.
- Bug Fixes:
  - Fixed lock screen screenshot path in README.

src/shared/window/dropdown.py

@@ -0,0 +1,90 @@
+from fabric.widgets.box import Box
+from fabric.widgets.centerbox import CenterBox
+from fabric.widgets.eventbox import EventBox
+from utils.roam import modus_service
+from shared.window.popup_window import PopupWindow
+
+dropdowns = []
+
+
+def dropdown_divider(comment):
+    return Box(
+        children=[Box(name="dropdown-divider", h_expand=True)],
+        name="dropdown-divider-box",
+        h_align="fill",
+        h_expand=True,
+        v_expand=True,
+    )
+
+
+class ModusDropdown(PopupWindow):
+    def __init__(self, dropdown_children=None, dropdown_id=None, **kwargs):
+        super().__init__(
+            layer="top",
+            exclusivity="auto",
+            name="dropdown-menu",
+            title="modus",
+            keyboard_mode="none",
+            visible=False,
+            **kwargs,
+        )
+
+        self.id = dropdown_id or str(len(dropdowns))
+        dropdowns.append(self)
+        self._mousecapture_parent = None  # Will be set by mousecapture
+
+        modus_service.connect("dropdowns-hide-changed", self.hide_dropdown)
+
+        self.dropdown = Box(
+            children=dropdown_children or [],
+            h_expand=True,
+            name="dropdown-options",
+            orientation="vertical",
+        )
+
+        self.child_box = CenterBox(start_children=[self.dropdown])
+
+        self.event_box = EventBox(
+            events=["enter-notify-event", "leave-notify-event"],
+            child=self.child_box,
+            all_visible=True,
+        )
+
+        self.children = [self.event_box]
+        self.add_keybinding("Escape", self.hide_dropdown)
+
+    def toggle_dropdown(self, button, parent=None):
+        self.set_visible(not self.is_visible())
+        modus_service.current_dropdown = self.id if self.is_visible() else None
+
+    def _init_mousecapture(self, mousecapture):
+        """Store reference to mousecapture parent for hiding"""
+        self._mousecapture_parent = mousecapture
+
+    def hide_dropdown(self, widget, event):
+        if self.is_visible():
+            self.hide()
+            if str(modus_service.current_dropdown) == str(self.id):
+                modus_service.current_dropdown = None
+
+    def hide_via_mousecapture(self):
+        """Hide dropdown via mousecapture parent"""
+        if self._mousecapture_parent:
+            self._mousecapture_parent.hide_child_window()
+
+    def _set_mousecapture(self, visible: bool) -> None:
+        self.set_visible(visible)
+        if visible:
+            modus_service.current_dropdown = self.id
+        else:
+            if str(modus_service.current_dropdown) == str(self.id):
+                modus_service.current_dropdown = None
+
+    def on_cursor_enter(self, *_):
+        self.set_visible(True)
+
+    def on_cursor_leave(self, *_):
+        if self.is_hovered():
+            return
+        self.set_visible(False)
+        modus_service.dropdowns_hide = not modus_service.dropdowns_hide