Expand Artgrid query coverage to artlist canonical URLs

TODO.md

@@ -128,6 +128,19 @@
 - Effect:
   - avoids backend 500 during the Gemini Vision evaluation stage for mid-sized result sets
 
+## Current Session Update (2026-03-13, Artgrid Query Coverage Fix)
+- Another Artgrid no-results regression was found even after the collector URL matcher was widened.
+- Root cause:
+  - Artgrid collector query generation still leaned on `site:artgrid.io/clip/`
+  - in practice, canonical clip pages can surface under `artlist.io/stock-footage/clip/...`
+  - so some Artgrid-only searches still returned zero renderable results even though the accept filter had been fixed
+- Fix applied:
+  - Artgrid query generation now searches both:
+    - `site:artgrid.io/clip/`
+    - `site:artlist.io/stock-footage/clip/`
+- Effect:
+  - improves Artgrid recall in SearXNG result sets that favor canonical Artlist URLs over Artgrid URLs
+
 ## Local Self-Test Workflow
 - Primary command:
   - `bash scripts/selftest.sh`