Hard paywalls (AFR etc.) block Googlebot by IP but serve full articles to
facebookexternalhit/Twitterbot for link previews. fetchBest() now fetches
several crawler identities concurrently and keeps the copy with the most text,
so the Reader works on AFR (0 -> 2256 words). Also rank archives first for
known hard-paywall domains.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>