fix(admin): persist image quota by setting remaining directly

Use PUT setImageQuota so admins can lower remaining below the stored plan
limit; grant-only bonus updates silently no-op when bonus is already zero.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/api/client.ts

@@ -1373,6 +1373,22 @@ export async function fetchUserImageQuota(userId: string) {
   }>(`/admin-api/users/${userId}/image-quota`);
 }
 
+export async function setUserImageQuota(
+  userId: string,
+  payload: { remaining?: number; total?: number },
+  note = '',
+) {
+  return portalFetch<{
+    ok: boolean;
+    unchanged?: boolean;
+    subscription: AdminSubscription;
+    quota: ImageQuotaView;
+  }>(`/admin-api/users/${userId}/image-quota`, {
+    method: 'PUT',
+    body: JSON.stringify({ ...payload, note }),
+  });
+}
+
 export async function grantUserImageQuota(userId: string, delta: number, note = '') {
   return portalFetch<{
     ok: boolean;