- Introduce Megatank: medium commander with Twin 150mm Cannon and Side Rocket Pods
- Implement multi-barrel weapon system (barrels + barrelSpacing) in TALogic and TARules
- Lower DEFENCE_MIN_SKILL from 4 to 3; make first Laser Tower proactive, not reactive
- Rebalance unit triangle: Tank now counters Rocket Tank; rockets weak vs vehicle armour
- Re-seed campaign missions m05 (67890) and m06 (80808) with updated maps and briefings
- Skirmish default theme uses rules default (tropics) instead of hardcoded grasslands
- Add intro video before main menu
- Update sprite docs and verification tests for new balance
