Add canonical Noctalia config and migrate Clipper to official plugin

- Create shared Noctalia config in dotfiles/desktop/.config/noctalia/
- Add Ayu theme, plugin enablement, and Clipper settings
- Migrate Clipper checkout from standalone to official noctalia-plugins
- Add template with host-specific variables for deterministic rendering
- Move Noctalia bar configuration to desktop group_vars
- Create role tasks for rendering and copying Noctalia settings

dotfiles/desktop/.config/noctalia/plugins.json

@@ -0,0 +1,24 @@
+{
+    "sources": [
+        {
+            "enabled": true,
+            "name": "Noctalia Plugins",
+            "url": "https://github.com/noctalia-dev/noctalia-plugins"
+        }
+    ],
+    "states": {
+        "clipper": {
+            "enabled": true,
+            "sourceUrl": "https://github.com/noctalia-dev/noctalia-plugins"
+        },
+        "polkit-agent": {
+            "enabled": true,
+            "sourceUrl": "https://github.com/noctalia-dev/noctalia-plugins"
+        },
+        "screenshot": {
+            "enabled": true,
+            "sourceUrl": "https://github.com/noctalia-dev/noctalia-plugins"
+        }
+    },
+    "version": 2
+}