Split frontend config API into file_config, server, and health modules

frontend/src/api/health.ts

@@ -0,0 +1,7 @@
+import { get } from "./client";
+import { ENDPOINTS } from "./endpoints";
+import type { HealthResponse } from "../types/server";
+
+export async function fetchHealth(): Promise<HealthResponse> {
+  return get<HealthResponse>(ENDPOINTS.health);
+}