release: v1.2.0 — unified images/ storage and legacy migration

Consolidate local images under data/images/, add docker migrate CLI,
startup index sync with orphan cleanup, and remove upload folder UI/API.

docker-compose.yml

@@ -10,6 +10,7 @@ services:
       - "6892:6892"
     # 首次访问 Web 引导创建管理员，无需预先配置环境变量
     # 可选：environment 中设置 API_UPLOAD_TOKEN、ALLOWED_REFERER_HOSTS 等
+    # 运维：docker exec pichost reset-password | migrate [--apply]
     volumes:
       # 冒号左边改成 NAS 上的实际存图目录（飞牛示例：/vol1/1000/pichost-data）
       - ./data:/data