Adds combat_turns metric (distinct turns where ≥1 bot died from enemy
focus-fire, excluding self-collisions). Worker computes it after each
match; index builder sorts matches/index.json and the new most-combat
playlist descending by it, and bumps interest score for combat-heavy
matches so they surface in highlights.
Also switches homepage featured replay default view from influence to
standard so the actual bot-on-bot combat is visible.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>