fix: add explicit GET method to API requests and make refresh interval reactive

- Add explicit method: 'GET' to ApiProxy.request() calls in polaris.ts and PolarisSettings.tsx
  for compatibility with Headlamp SDK
- Make refresh interval reactive by polling localStorage every second in PolarisDataContext
  so settings changes take effect immediately without page reload

Fixes connection test button and data refresh issues.

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>

src/api/PolarisDataContext.tsx

@@ -35,8 +35,20 @@ const PolarisDataContext = React.createContext<PolarisDataContextValue | null>(n
  * ```
  */
 export function PolarisDataProvider(props: { children: React.ReactNode }) {
-  const interval = getRefreshInterval();
-  const state = usePolarisData(interval);
+  // Re-read interval on every render to pick up changes from settings
+  const [refreshInterval, setRefreshInterval] = React.useState(getRefreshInterval());
+
+  // Poll for interval changes (localStorage changes from settings)
+  React.useEffect(() => {
+    const intervalId = window.setInterval(() => {
+      const newInterval = getRefreshInterval();
+      setRefreshInterval(prev => (prev !== newInterval ? newInterval : prev));
+    }, 1000); // Check every second
+
+    return () => window.clearInterval(intervalId);
+  }, []);
+
+  const state = usePolarisData(refreshInterval);
 
   // Rename triggerRefresh to refresh for consistency
   const value = React.useMemo(

src/api/polaris.ts

@@ -373,7 +373,9 @@ export function usePolarisData(refreshIntervalSeconds: number): PolarisDataState
           result = await response.json();
         } else {
           // Kubernetes proxy for relative URLs
-          result = await ApiProxy.request(apiPath);
+          result = await ApiProxy.request(apiPath, {
+            method: 'GET',
+          });
         }
 
         if (!cancelled) {

src/components/PolarisSettings.tsx

@@ -58,7 +58,9 @@ export default function PolarisSettings(props: PluginSettingsProps) {
         }
         result = await response.json();
       } else {
-        result = await ApiProxy.request(apiPath);
+        result = await ApiProxy.request(apiPath, {
+          method: 'GET',
+        });
       }
 
       setTestResult({