put shell in subdir, and add nix package

shell/lockscreen/Controller.qml

@@ -0,0 +1,44 @@
+pragma Singleton
+pragma ComponentBehavior: Bound
+
+import Quickshell
+import Quickshell.Io
+import Quickshell.Wayland
+
+Singleton {
+    id: root
+
+    PersistentProperties {
+        id: persist
+        property bool locked: false
+    }
+
+    IpcHandler {
+        target: "lockscreen"
+
+        function lock(): void {
+            persist.locked = true;
+        }
+    }
+
+    LockContext {
+        id: passwordContext
+
+        onUnlocked: persist.locked = false
+    }
+
+    WlSessionLock {
+        id: lock
+
+        locked: persist.locked
+
+        WlSessionLockSurface {
+            LockSurface {
+                anchors.fill: parent
+                context: passwordContext
+            }
+        }
+    }
+
+    function init() {}
+}