fix: manifest diff shows all resources as recreated (#672) (#673)

The manifests endpoint returns text/plain YAML, but fetchWithSafeDefaults
treats string responses as errors and returns the fallback value ([]).
Revert useGetReleaseManifest to use fetchWithDefaults which correctly
passes through text/plain responses.

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/API/releases.ts

@@ -65,15 +65,14 @@ export function useGetReleaseManifest({
 }: {
   namespace: string;
   chartName: string;
-  options?: UseQueryOptions<ReleaseManifest[]>;
+  options?: UseQueryOptions<string>;
 }) {
-  return useQuery<ReleaseManifest[]>({
+  return useQuery<string>({
     queryKey: ["manifest", namespace, chartName],
     queryFn: () =>
-      apiService.fetchWithSafeDefaults<ReleaseManifest[]>({
+      apiService.fetchWithDefaults<string>(
-        url: `/api/helm/releases/${namespace}/${chartName}/manifests`,
+        `/api/helm/releases/${namespace}/${chartName}/manifests`
-        fallback: [],
+      ),
-      }),
     ...(options ?? {}),
   });
 }

frontend/src/components/modal/InstallChartModal/InstallReleaseChartModal.tsx

@@ -143,7 +143,7 @@ export const InstallReleaseChartModal = ({
   } = useDiffData({
     selectedRepo,
     versionsError: versionsError as unknown as string, // TODO fix it
-    currentVerManifest: currentVerManifest as unknown as string, // TODO fix it
+    currentVerManifest: currentVerManifest ?? "",
     selectedVerData,
     chart: chartAddress,
   });