fix: use package name for registerPluginSettings, not directory name

Headlamp identifies plugins by their package.json name (headlamp-polaris),
not the deploy directory name (polaris). The previous commit incorrectly
changed this to 'polaris', causing the settings component to never render
in the plugin settings page — breaking all 5 E2E settings tests.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

src/index.tsx

@@ -99,7 +99,7 @@ registerRoute({
 });
 
 // Register plugin settings
-registerPluginSettings('polaris', PolarisSettings, true);
+registerPluginSettings('headlamp-polaris', PolarisSettings, true);
 
 // Register details view section for supported controller types
 registerDetailsViewSection(({ resource }) => {