feat: skill-email 프록시 설정 추가

- /skill-email/ → http://localhost:8501/ 프록시 추가
- 포트 8501에서 실행되는 skill-email 서비스 연결

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

server-nginx-default

@@ -160,6 +160,15 @@ server {
             proxy_set_header X-Forwarded-Proto $scheme;
         }
 
+        # Skill Email API endpoints
+        location /skill-email/ {
+            proxy_pass http://localhost:8501/;
+            proxy_set_header Host $host;
+            proxy_set_header X-Real-IP $remote_addr;
+            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+            proxy_set_header X-Forwarded-Proto $scheme;
+        }
+
         location /.well-known/acme-challenge/ {
             alias /var/www/html/.well-known/acme-challenge/;
         }