Changes:
1. Reduce 2-player spawn radius from 25% to 12.5% (bots start ~10 tiles apart,
within 5-tile attack radius vs 20 tiles apart before)
2. Reduce zone shrink step from 2 to 1 tiles/turn (zone shrinks at same rate
as bot movement instead of faster)
3. Reduce initial zone margin from 10 to 5 tiles (faster engagement)
Testing results:
- Random vs Random: 92% combat density (46/50 matches) - was 20%
- All strategy combinations: 100% combat density
- Target: 65-80% per plan §3.7.1
The key issue was that bots started too far apart and the zone shrank faster
than bots could move toward each other. By starting closer and slowing the
zone shrink rate, bots now engage in combat before the zone kills them.
Closes: bf-cssy
62f94ff0ef