fix: improve theming and settings visibility

- Fix namespace detail panel to follow system dark/light theme
- Use proper CSS custom properties for background and text colors
- Fix plugin settings registration (remove deprecated third parameter)
- Ensure close button and headers respect theme colors
- Version bump to 0.2.5

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>

artifacthub-pkg.yml

@@ -1,4 +1,4 @@
-version: 0.2.4
+version: 0.2.5
 name: headlamp-polaris-plugin
 displayName: Polaris
 createdAt: "2026-02-05T19:00:00Z"
@@ -28,7 +28,7 @@ maintainers:
   - name: cpfarhood
     email: "chris@farhood.org"
 annotations:
-  headlamp/plugin/archive-url: "https://github.com/cpfarhood/headlamp-polaris-plugin/releases/download/v0.2.4/headlamp-polaris-plugin-0.2.4.tar.gz"
+  headlamp/plugin/archive-url: "https://github.com/cpfarhood/headlamp-polaris-plugin/releases/download/v0.2.5/headlamp-polaris-plugin-0.2.5.tar.gz"
   headlamp/plugin/version-compat: ">=0.26"
-  headlamp/plugin/archive-checksum: sha256:f619640371dc2d18e0a8eca03ed046ed4adc3a3c11468fc192e536b324f82914
+  headlamp/plugin/archive-checksum: sha256:0000000000000000000000000000000000000000000000000000000000000000
   headlamp/plugin/distro-compat: in-cluster