Merge pull request #21 from DguFarmSystem/fix/#16

fix: Vercel 라우팅 문제 해결을 위한 vercel.json 추가

Author: dewbeeny

vercel.json

@@ -0,0 +1,6 @@
+{
+  "rewrites": [
+    { "source": "/auth/callback", "destination": "/index.html" },
+    { "source": "/(.*)", "destination": "/index.html" }
+  ]
+}