ui(api): add useDirtyState + apply=staged|live on useUpdateApplicationConfig

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ui/src/api/queries/admin/apps.ts

@@ -203,3 +203,27 @@ export function usePromoteDeployment() {
     onSuccess: () => qc.invalidateQueries({ queryKey: ['apps'] }),
   });
 }
+
+// --- Dirty State ---
+
+export interface DirtyStateDifference {
+  field: string;
+  staged: string;
+  deployed: string;
+}
+
+export interface DirtyState {
+  dirty: boolean;
+  lastSuccessfulDeploymentId: string | null;
+  differences: DirtyStateDifference[];
+}
+
+export function useDirtyState(envSlug: string | undefined, appSlug: string | undefined) {
+  return useQuery({
+    queryKey: ['apps', envSlug, appSlug, 'dirty-state'],
+    queryFn: () => apiFetch<DirtyState>(
+      `${envBase(envSlug!)}/${encodeURIComponent(appSlug!)}/dirty-state`,
+    ),
+    enabled: !!envSlug && !!appSlug,
+  });
+}