KnownListBuilder.MineCopyTokens resolves a copy add's baseIdx against the actor's own idx->cardId map (self/other by isSelf), yielding (idx,cardId, isSelf). Skips concrete/choice adds, string (private-group) baseIdx, and unknown sources (degrade). Third token-reveal slice. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>