FEAT: Video Search In Discovery

tests/README.md

@@ -77,6 +77,19 @@ Both steps of the upload flow, end to end:
   not there at all, and a video announced a second time is updated rather than
   colliding with its own row
 
+- searching that catalogue over `QUERY /api/videos`: finding a video by a word
+  in its title and by a part-typed one, narrowing to a category and being left
+  out of another, several categories meaning "any of", paging by cursor so the
+  pages tile the results exactly once, refusing a cursor no search issued, and
+  capping a page size that asks for the whole catalogue
+
+Search scenarios give every video they catalogue a nonce in its title, and
+assert relative to the video they created ("returns that video") rather than on
+absolute counts. Nothing cleans up between runs, so a fixed title accumulates a
+copy per run and a count would stop meaning anything. The paging scenario shares
+one nonce across its videos so that searching for it matches that run's cohort
+and nothing else.
+
 The publication scenarios read `tests-catalogue-events`, the suite's **own**
 queue on the catalogue topic — not discovery's. A consumer destroys what it
 reads, so sharing discovery's queue would have the suite and the running