feat(infra): configure oss.gogenex.com domain for MinIO object storage

按域名规划文档为 MinIO 配置专属域名访问。

变更内容：

DNS（Namecheap）
- 新增 A 记录：oss.gogenex.com → 154.84.135.121

Nginx（网关服务器 14.215.128.96）
- 新增 /etc/nginx/conf.d/oss.gogenex.com.conf
- 反代配置：oss.gogenex.com → localhost:9100
- client_max_body_size 500m（支持大文件 APK/IPA 上传）
- proxy_request_buffering off（流式上传，不缓冲至磁盘）
- Let's Encrypt SSL 证书已签发

backend/docker-compose.yml
- MINIO_ENDPOINT: 192.168.1.200 → oss.gogenex.com
- MINIO_PORT: 9100 → 443
- 新增 MINIO_USE_SSL=true

infrastructure/minio/docker-compose.yml
- 补充域名访问注释说明

服务器现状：
  admin-service 已重启，MinIO 通过 https://oss.gogenex.com 访问。

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/docker-compose.yml

@@ -353,8 +353,9 @@ services:
       - DB_USERNAME=genex
       - DB_PASSWORD=${DB_PASSWORD}
       - DB_NAME=genex
-      - MINIO_ENDPOINT=192.168.1.200   # Gateway server — MinIO runs on 192.168.1.200:9100
-      - MINIO_PORT=9100
+      - MINIO_ENDPOINT=oss.gogenex.com  # Object storage — https://oss.gogenex.com (gateway server)
+      - MINIO_PORT=443
+      - MINIO_USE_SSL=true
       - MINIO_ACCESS_KEY=genex-admin
       - MINIO_SECRET_KEY=genex-minio-secret
       - MINIO_BUCKET=app-releases

infrastructure/minio/docker-compose.yml

@@ -1,3 +1,8 @@
+# MinIO Object Storage — deployed on gateway server (154.84.135.121 / 192.168.1.200)
+# Public domain : https://oss.gogenex.com  (Nginx SSL termination → localhost:9100)
+# Console       : http://192.168.1.200:9101
+# Credentials   : see .env or deploy.sh defaults
+
 services:
   minio:
     image: minio/minio