Fix deny list: make valid JSON, keep only non-talk entries
The comment-stripping regex was matching // inside at:// URIs,
silently corrupting every entry so the deny list filtered nothing.
Removed comments from the JSON file and simplified parsing to plain
JSON.parse. Also trimmed the list to only non-talk entries (starting
soon, lunch, join us, duplicates) — all actual talks are now included.
Reduced audio ready-wait timeout from 3s to 1s.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>