fix: send Supabase token on raw fetch in SaaS chat

frontend/editor/src/core/services/apiClientSetup.ts

@@ -13,7 +13,11 @@ export function setupApiInterceptors(client: AxiosInstance): void {
   );
 }
 
-/** Auth headers for raw fetch() calls (SSE streams, etc.). Proprietary overrides with JWT + XSRF. */
-export function getAuthHeaders(): Record<string, string> {
+/**
+ * Auth headers for raw fetch() calls (SSE streams, etc.).
+ * Proprietary overrides with stored JWT + XSRF; SaaS overrides with the live
+ * Supabase access token. Async because SaaS has to consult the auth client.
+ */
+export async function getAuthHeaders(): Promise<Record<string, string>> {
   return {};
 }