Add superpowers system: 9 abilities with cooldowns, research unlocks master
- New superpowers module with 9 powers (Evil Laugh, Death Ray, Dark Regeneration, Emergency Reinforcements, Force Wave, Soul Drain, Impenetrable Shield, Blink, Plague Cloud) - Powers unlocked via research tree + notoriety thresholds - Combat integration: activate_power() handles all effects - Invulnerability blocks throne attacks, repels agents - Terminal: number keys 1-9 during defend, sidebar display - Bevy: number keys 1-9, UI text display, cooldown ticking - Renamed all Overlord/Evil Genius references to Supervillain - 98 tests passing (4 new superpower combat tests) 👾 Generated with [Letta Code](https://letta.com) Co-Authored-By: Letta Code <noreply@letta.com>