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/utils/dbus_helper.py

@@ -0,0 +1,83 @@
+from fabric.utils import Gio, GLib
+
+
+class GioDBusHelper:
+    """A helper class for interacting with D-Bus using the Gio library."""
+
+    def __init__(
+        self,
+        bus_name,
+        object_path,
+        interface_name,
+        bus_type=Gio.BusType.SYSTEM,
+    ):
+        self.bus = Gio.bus_get_sync(bus_type, None)
+
+        self.bus_name = bus_name
+        self.object_path = object_path
+        self.proxy = Gio.DBusProxy.new_sync(
+            self.bus,
+            Gio.DBusProxyFlags.NONE,
+            None,
+            bus_name,
+            object_path,
+            interface_name,
+            None,
+        )
+
+    def call_method(
+        self,
+        bus_name,
+        object_path,
+        interface_name,
+        method_name,
+        parameters=None,
+        timeout=-1,
+    ):
+        if parameters is None:
+            parameters = GLib.Variant("()", ())
+        result = self.bus.call_sync(
+            bus_name,
+            object_path,
+            interface_name,
+            method_name,
+            parameters,
+            None,
+            Gio.DBusCallFlags.NONE,
+            timeout,
+            None,
+        )
+        return result.unpack()
+
+    def listen_signal(
+        self, member, callback, interface_name="org.freedesktop.DBus.Properties"
+    ):
+        """Register a signal listener (conn, sender, path, iface, signal, parameters). Returns subscription id."""
+        return self.bus.signal_subscribe(
+            self.bus_name,
+            interface_name,
+            member,
+            self.object_path,
+            arg0=None,
+            flags=Gio.DBusSignalFlags.NONE,
+            callback=callback,
+        )
+
+    def unsubscribe_signal(self, subscription_id: int):
+        """Unsubscribe a previously registered signal using its subscription id."""
+        try:
+            self.bus.signal_unsubscribe(subscription_id)
+        except Exception:
+            pass
+
+    def set_property(self, interface_name, property_name, value_variant):
+        """Sets a D-Bus property using the standard D-Bus Properties interface."""
+        return self.call_method(
+            bus_name=self.bus_name,
+            object_path=self.object_path,
+            interface_name="org.freedesktop.DBus.Properties",
+            method_name="Set",
+            parameters=GLib.Variant(
+                "(ssv)", (interface_name, property_name, value_variant)
+            ),
+        )