Include oversized Synology photos through existing read-only XL previews

docs/PHOTO_SOURCES.md

@@ -119,3 +119,11 @@ Output is 1200×1600: a 1200×1280 photo area plus a white caption area. Origina
 files remain unchanged. Contain/cover/smart and color/grayscale profiles still apply.
 A prepared source definition is in `deploy/organized-photos-source.json`; use it
 with `PUT /api/v1/photo-sources/organized-photos` after mounting the library.
+
+For Synology Photos shared libraries, `synology_previews: true` allows images over
+20 MiB to use their existing `@eaDir/<filename>/SYNOPHOTO_THUMB_XL.jpg` preview.
+This is a read-only fallback: original files and Photos indexes remain unchanged,
+no thumbnails are generated on the NAS, and the ordinary size limit still applies
+to the selected preview. The catalog marks these entries `provider_preview: true`.
+If the preview is missing, the oversized original remains excluded. The folder
+caption still comes from the original curated directory.

docs/openapi.json

@@ -10326,6 +10326,11 @@
               }
             ],
             "title": "Caption"
+          },
+          "provider_preview": {
+            "type": "boolean",
+            "title": "Provider Preview",
+            "default": false
           }
         },
         "additionalProperties": false,
@@ -10416,6 +10421,11 @@
             "title": "Catalog Limit",
             "default": 10000
           },
+          "synology_previews": {
+            "type": "boolean",
+            "title": "Synology Previews",
+            "default": false
+          },
           "organized_only": {
             "type": "boolean",
             "title": "Organized Only",
@@ -10487,6 +10497,11 @@
             "title": "Catalog Limit",
             "default": 10000
           },
+          "synology_previews": {
+            "type": "boolean",
+            "title": "Synology Previews",
+            "default": false
+          },
           "organized_only": {
             "type": "boolean",
             "title": "Organized Only",