chore: keep generated images inside the project as real directories

The absolute-path + symlink layout added earlier today is awkward to
redeploy against: after a fresh clone the symlinks point at nothing and
compose quietly creates empty directories in their place, so the service
comes up healthy with no history.

/root/apps/ holds services only, so the images and the SQLite database
live in the project again as ./output and ./data, bind-mounted with
relative paths. Backups are handled by a separate hook that copies to
/root/backup_files/ai-image/, which is not part of /root/apps/.

Both directories stay gitignored.

docker-compose.yml

@@ -8,9 +8,12 @@ services:
     env_file:
       - .env
     volumes:
-      # 生成物与数据库放在 git 工作树外（/root/apps/ai-image 是 git repo，
-      # 目录一旦被 clone/rm 重建，未跟踪的生成物会一起消失 —— 2026-11-04 丢过一轮）。
-      # 用绝对路径而非 ./output，避免 bind mount 跟随符号链接的歧义。
-      - /root/apps/ai-image-data/output:/app/output
-      - /root/apps/ai-image-data/data:/app/data
+      # 生成物与数据库用项目内相对路径（2026-11-04 还原）。
+      # 不用绝对路径也不用符号链接：符号链接在重新 clone/rm -rf 重建后
+      # 会指向空气，compose 还会静默创建一个空目录。
+      # 注意：/root/apps/ai-image/output 与 /root/apps/ai-image/data 是本服务的
+      # 生成物目录，删项目之前先备份（备份脚本见 ruantang profile 的
+      # backup-ai-image-output.sh，落到 /root/backup_files/ai-image/）。
+      - ./output:/app/output
+      - ./data:/app/data
     restart: unless-stopped