feat: add QR Generator launcher (#2941)

* feat: add QR Generator modal with auto-generate on input debounce

- QRGeneratorModal with dual-buffer sequential fade animation
- Auto-generate QR code on typing stop (200ms debounce)
- Clear text button on input field
- Escape key closes modal
- Register modal in PopoutService and AppSearchService
- Go backend for text QR code generation

* fix: add QR Generator toggle to Launcher DMS settings

* qr: also add qrg built in launcher plugin

---------

Co-authored-by: bbedward <bbedward@gmail.com>

quickshell/DMSShell.qml

@@ -445,6 +445,23 @@ Item {
         }
     }
 
+    LazyLoader {
+        id: qrGeneratorModalLoader
+        active: false
+
+        Component.onCompleted: {
+            PopoutService.qrGeneratorModalLoader = qrGeneratorModalLoader;
+        }
+
+        QRGeneratorModal {
+            id: qrGeneratorModalItem
+
+            Component.onCompleted: {
+                PopoutService.qrGeneratorModal = qrGeneratorModalItem;
+            }
+        }
+    }
+
     LazyLoader {
         id: polkitAuthModalLoader
         active: false