improve handling of images from immich albums

README.md

@@ -167,7 +167,7 @@ Immich control topic (`immichTopic`):
 
 ### Immich configuration (lightweight + low power)
 
-Immich uses an API key and a `/api` base path. This integration requests the asset search endpoint and downloads the configured image size into a local cache before displaying them. That keeps bandwidth and power usage low while still letting `slide` do its normal scaling and transitions. If you have RAW images, set `size` to `preview`/`thumbnail` or use `extensions` to limit results to JPEG/PNG.
+Immich uses an API key and a `/api` base path. This integration requests the asset search endpoint and downloads the configured image size into a local cache before displaying them. That keeps bandwidth and power usage low while still letting `slide` do its normal scaling and transitions. If you have RAW/HEIC images, set `size` to `preview`/`thumbnail` or use `extensions` to limit results to JPEG/PNG; `slide` will also fall back to `preview` if a `fullsize` download isn't readable.
 
 #### Getting an Immich API key
 
@@ -191,6 +191,7 @@ Example (single source):
     "order": "desc",
     "pageSize": 200,
     "maxAssets": 1000,
+    "refreshSeconds": 300,
     "cachePath": "~/.cache/slide/immich",
     "cacheMaxMB": 512,
     "includeArchived": false
@@ -226,6 +227,7 @@ Immich settings:
 * `order`: `"asc"` or `"desc"` ordering for asset search.
 * `pageSize`: assets fetched per page.
 * `maxAssets`: cap on total assets fetched (0 means no cap).
+* `refreshSeconds`: refresh interval for reloading Immich assets (0 disables).
 * `cachePath`: local cache directory for downloaded images.
 * `cacheMaxMB`: maximum cache size in MB (0 disables cleanup).
 * `includeArchived`: include archived assets in search results.