feat: integrate Kakao OAuth for user authentication and enhance user repository

- Added Kakao OAuth client implementation for handling authentication flows.
- Updated user repository to support OAuth-based user creation and retrieval.
- Introduced Redis-based session management for OAuth sessions.
- Enhanced in-memory user repository to handle OAuth user data.
- Updated environment configuration files to include new OAuth settings.
- Modified API routes to support Kakao login and registration flows.
- Added Prisma schema updates for user model to accommodate OAuth fields.
- Implemented tests for the new authentication flow and user repository methods.

.env.ci.example

@@ -2,3 +2,17 @@ POSTGRES_DB=sammo_test
 POSTGRES_USER=sammo
 POSTGRES_PASSWORD=ci-postgres
 REDIS_PASSWORD=ci-redis
+REDIS_HOST=127.0.0.1
+REDIS_PORT=16379
+REDIS_DB=0
+GAME_TOKEN_SECRET=ci-secret
+GATEWAY_REDIS_PREFIX=sammo:gateway
+GATEWAY_API_HOST=127.0.0.1
+GATEWAY_API_PORT=13000
+GATEWAY_PUBLIC_URL=http://localhost:13000
+GAME_API_HOST=127.0.0.1
+GAME_API_PORT=14000
+PROFILE=che
+SCENARIO=default
+KAKAO_REST_KEY=ci-kakao-rest-key
+KAKAO_REDIRECT_URI=http://localhost:13000/oauth/kakao/callback