ci(config): add GHCR image publish workflow

Publish frontend, backend, and remote-gateway images to GHCR on
pushes to main and manual runs. Also update docker-compose to pull
the three service images from ghcr.io instead of Docker Hub.

.helloagents/archive/_index.md

@@ -7,12 +7,12 @@
 
 | 时间戳 | 名称 | 类型 | 涉及模块 | 决策 | 结果 |
 |--------|------|------|---------|------|------|
-| 暂无 | - | - | - | - | - |
+| 202603250317 | ghcr-docker-publish | implementation | workspace-root | ghcr-docker-publish#D001 | ✅完成 |
 
 ## 按月归档
 
 ### 2026-03
-- 暂无已归档方案
+- [202603250317_ghcr-docker-publish](./2026-03/202603250317_ghcr-docker-publish/) - 新增 GHCR 镜像发布 workflow 并切换 compose 镜像来源
 
 ## 结果状态说明
 - ✅ 完成