docs: update server setup guides and add domain-based nginx config

CLAUDE.md

@@ -1628,7 +1628,7 @@ curl http://127.0.0.1/taxbaik/admin/login
 ### E2E 테스트 & 반응형 검증
 ```bash
 # 문의 폼 제출
-curl -X POST http://178.104.200.7/taxbaik/contact \
+curl -X POST http://taxbaik.com/taxbaik/contact \
   -d "name=테스트&phone=010-1234-5678&service_type=사업자세무&message=테스트"
 
 # 관리자 DB에서 확인
@@ -1667,7 +1667,7 @@ npx playwright test admin-responsive.spec.ts --project="Desktop Chrome"
 
 **프로덕션 E2E 테스트**:
 ```bash
-export E2E_BASE_URL="http://178.104.200.7/taxbaik"
+export E2E_BASE_URL="http://taxbaik.com/taxbaik"
 export E2E_ADMIN_USERNAME="test_admin"
 export E2E_ADMIN_PASSWORD="TestAdmin@123456"
 
@@ -1935,7 +1935,7 @@ else
 2. **Actions run 생성 확인**
    ```powershell
    $headers = @{ Authorization = "token $env:GITEA_TOKEN_TAXBAIK" }
-   $runs = Invoke-RestMethod -Headers $headers -Uri "http://178.104.200.7/api/v1/repos/kjh2064/taxbaik/actions/runs?limit=10"
+   $runs = Invoke-RestMethod -Headers $headers -Uri "http://gitea.taxbaik.com/api/v1/repos/kjh2064/taxbaik/actions/runs?limit=10"
    $runs.workflow_runs | Select-Object id,path,event,head_sha,display_title,status,conclusion
    ```
    `deploy.yml@refs/heads/master`, `event=push`, 최신 `head_sha`가 있어야 배포가 실제로 시작된 것이다.