fix: rename plugin from headlamp-intel-gpu to intel-gpu

The settings page showed "headlamp-intel-gpu" instead of "intel-gpu".
The package name determines the plugin's display name in Headlamp settings.
Other plugins (kube-vip, sealed-secrets) use short names — this aligns
the intel-gpu plugin with the same convention.

Fixes PRI-76

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -1,5 +1,5 @@
 {
-  "name": "headlamp-intel-gpu",
+  "name": "intel-gpu",
   "version": "0.4.2",
   "description": "Headlamp plugin for Intel GPU device plugin visibility and monitoring",
   "repository": {