fix(youtube): pass full transcripts to LLM instead of truncating to 200 chars

TRANSCRIPT_MAX_WORDS raised from 500 to 5000 so the LLM gets the full
content of most videos (up to ~25 minutes). Removed the second 200-char
truncation in render.py that was reducing transcripts to a single sentence
before the judge agent ever saw them.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

scripts/lib/youtube_yt.py

@@ -33,7 +33,7 @@ TRANSCRIPT_LIMITS = {
 }
 
 # Max words to keep from each transcript
-TRANSCRIPT_MAX_WORDS = 500
+TRANSCRIPT_MAX_WORDS = 5000
 
 from .relevance import token_overlap_relevance as _compute_relevance