feat(ai-character): Mock Preview 모드 구현

package.json

@@ -4,7 +4,8 @@
   "private": true,
   "type": "module",
   "scripts": {
-    "dev": "vite --host 127.0.0.1 --port 8888 --strictPort",
+    "dev": "VITE_API_MODE=server vite --host 127.0.0.1 --port 8888 --strictPort",
+    "dev:mock": "VITE_API_MODE=mock vite --host 127.0.0.1 --port 8889 --strictPort",
     "build": "npm run build:prod",
     "build:dev": "tsc -b && vite build --mode development",
     "build:prod": "tsc -b && vite build --mode production",
@@ -12,7 +13,8 @@
     "lint": "eslint .",
     "test": "vitest",
     "test:run": "vitest run",
-    "e2e": "playwright test"
+    "e2e": "VITE_API_MODE=server playwright test",
+    "e2e:mock": "VITE_API_MODE=mock playwright test"
   },
   "dependencies": {
     "@tanstack/react-query": "^5.101.4",
@@ -43,5 +45,10 @@
     "typescript-eslint": "8.65.0",
     "vite": "8.1.5",
     "vitest": "4.1.10"
+  },
+  "msw": {
+    "workerDirectory": [
+      "public"
+    ]
   }
 }