feat: add Metrics page, remove app bar badge, fix sidebar label

- Add src/api/metrics.ts: Prometheus text parser + fetchGpuPluginMetrics()
  fetching from Intel GPU device plugin pods (port 9090). Extracts engine
  utilization (active/total ticks → %), boost frequency (MHz), VRAM and
  system memory usage, cumulative energy (µJ).

- Add src/components/MetricsPage.tsx: per-card metrics display with inline
  utilization bars, graceful fallback when enableMonitoring is not set.

- Register Metrics sidebar entry (mdi:chart-line) and route /intel-gpu/metrics.

- Remove registerAppBarAction and AppBarGpuBadge (colored info bubble).

- Fix sidebar parent label: 'Intel GPU' → 'intel-gpu'.

- Bump to v0.2.0; update artifacthub-pkg.yml with new archive URL and checksum.

Generated with [Claude Code](https://claude.ai/code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "headlamp-intel-gpu-plugin",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "description": "Headlamp plugin for Intel GPU device plugin visibility and monitoring",
   "repository": {
     "type": "git",