feat(ai-character): Mock Preview 모드 구현

src/shared/mocks/browser.ts

@@ -0,0 +1,11 @@
+import { setupWorker } from "msw/browser";
+
+import { getRuntimeEnv } from "@/shared/config/env";
+import { createMockHandlers, createMockStore } from "@/shared/mocks/handlers";
+
+let worker: ReturnType<typeof setupWorker> | null = null;
+
+export async function startMockWorker(): Promise<void> {
+  worker ??= setupWorker(...createMockHandlers(createMockStore(), getRuntimeEnv().apiBaseUrl));
+  await worker.start({ onUnhandledRequest: "error" });
+}