Document verified Photos API candidate image and migration boundaries

README.md

@@ -37,7 +37,9 @@ python3.14 -m venv .venv
 
 The demo forces mock mode and disables device writes. Data and configuration remain in `data/` and `config/` across restarts.
 
-### Features and boundaries
+#Synology Photos API sources work without `/photos` or NFS mounts, with shared/current-account personal spaces, people filters and bounded on-demand XL preview caching. Original downloads are not supported by this verified implementation. See [Photos API and Ubuntu migration candidate](docs/SYNOLOGY_PHOTOS_API.md).
+
+## Features and boundaries
 
 - Chinese and English Web UI, light/dark themes, account login, device dashboard and image previews.
 - Local staging and KoKonna cloud gallery, uploads, image switching, stars, source/task filters and batch actions.

README.zh-CN.md

@@ -37,7 +37,9 @@ python3.14 -m venv .venv
 
 演示强制使用 Mock，并关闭设备写入。数据与配置保存在 `data/`、`config/`，重启后保留。
 
-### 功能与边界
+#Synology Photos 可使用独立的 API 来源，无需 `/photos` 或 NFS 挂载；支持共享 / 当前账号个人空间、人物筛选和按需 XL 预览缓存。原图下载不在本次已验证支持范围内。见 [API 来源与 Ubuntu 候选迁移说明](docs/SYNOLOGY_PHOTOS_API.md)。
+
+## 功能与边界
 
 - 中英文 Web 界面、深浅色主题、账号登录、设备面板与图片预览。
 - NAS 本地图库和 KoKonna 云端图库；星标、来源/任务筛选及批量操作位于本地图库，上传到云端并显示需单独操作。

docs/PHOTO_SOURCES.md

@@ -4,6 +4,10 @@ Photo sources are independent read-only providers. They never call a frame drive
 SQLite persists source definitions and Scheduler jobs; passwords are not stored there.
 The shared DisplayService handles fitting, upload, idempotency, overrides and restore.
 
+## Synology Photos API (no mount)
+
+Use the explicit `synology-photos` source type for Ubuntu without `/photos`. Existing local sources are not silently converted. Shared and current-account personal spaces use the shared Photos login, with ID-based any/all people filters and bounded XL preview caching. See [verified capabilities, migration and recovery](SYNOLOGY_PHOTOS_API.md). Original API downloads remain unsupported.
+
 ## NAS local folder
 
 Add the actual existing photo directory to `.env`: