update spec

SPEC.md

@@ -96,12 +96,34 @@ Requires an administrator API key.
 Serves the pause-overlay script that JRay injects into the web client's
 `index.html` (see below). Anonymous access.
 
+### `GET /Plugins/JRay/Tasks/Pending?limit=10`
+
+Lets a remote extraction worker discover what to work on next. Returns a
+random sample (default 10, max 100) of movies/episodes in the library that
+have no truth data yet (neither a managed upload nor a sidecar file):
+
+```json
+[
+  { "item_id": "abc123-guid", "path": "/data/movies/Movie.mkv", "name": "Movie" }
+]
+```
+
+Requires an administrator API key. The sample is random and unordered, so
+repeated polling naturally spreads work across the backlog without needing
+server-side task tracking; an empty array means there's nothing left to do
+(or every remaining item is a virtual/missing-path item that JRay can't
+process).
+
 ## Client: pushing results from a remote extraction worker
 
 A worker that runs the extraction pipeline on a different machine than
 Jellyfin (i.e. it cannot write a `Movie.jray.json` sidecar next to the media
 file) can push results directly over HTTP.
 
+To find work, poll `GET /Plugins/JRay/Tasks/Pending?limit=10` (see above) for
+a random batch of items that still need processing, instead of walking the
+whole library and checking each item's `Timeline`/sidecar yourself.
+
 ### 1. Authenticate
 
 Create an **Administrator** API key in Jellyfin (Dashboard → API Keys), and