Add Noctalia shell with Quickshell overview

- Add `noctalia` input to flake and lock it in `flake.lock`.
- Include `noctalia` and `quickshell` modules in `flake.nix`.
- Extend core packages to accept `inputs` and `system`; add
  `quickshell.nix`
  with required Qt6 packages and environment variables.
- Enable `upower` service for battery handling.
- Add home modules `noctalia.nix` and `overview.nix` (QML UI, README,
  assets, widgets, services) to provide a workspace overview.
- Comment out unused rofi and web‑search binds; update `exec‑once` to
  start
  the overview daemon and `noctalia-shell`.
- Provide `restart.noctalia` script and its Nix wrapper.
- Enable `noctalia-shell` in `stylix` configuration.

modules/home/overview/shell.qml

@@ -0,0 +1,16 @@
+//@ pragma UseQApplication
+//@ pragma Env QT_QUICK_CONTROLS_STYLE=Basic
+
+import "./modules/overview/"
+import "./services/"
+import "./common/"
+import "./common/functions/"
+import "./common/widgets/"
+
+import QtQuick
+import Quickshell
+import Quickshell.Hyprland
+
+ShellRoot {
+    Overview {}
+}