Township: allow keyframes/keyframe scopes in /matches/render

The render endpoint's scope allowlist rejected the new keyframe-regen
scopes with a 400 before reaching the handler. Add them so the
"Regenerate keyframes" / per-clip kf↻ buttons work.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tools/gen_township_fighters.py

@@ -5086,7 +5086,7 @@ async function pollJob(){
 
                 scope = _fv("scope")
                 if scope not in ("match-clips", "clip", "reassemble", "outcomes",
-                                 "outcome", "enhance"):
+                                 "outcome", "enhance", "keyframes", "keyframe"):
                     self._send(400, "application/json",
                                _j.dumps({"error": "invalid scope"}))
                     return