Three bugs caused the radar to sweep continuously instead of locking:
1. run() loop set radar to Inf every tick, overwriting any lock
→ replaced with enemy_tracker.getRadarTurnRate()
2. onScannedBot used radarBearingTo() (math convention, east=0 CCW)
→ removed; run loop now handles radar via enemy_tracker
3. enemy_tracker.getRadarTurnRate() had arctan2(dx,dy) instead of
arctan2(dy,dx) — introduced by fd22535; bearing was off by ~90°
Also relaxed stale-lock threshold from 2 to 8 ticks to survive
brief scan gaps without falling back to full sweep.
Added tools/battle_runner for automated 1v1 testing.
Result: 1303/1308 ticks with successful scan (was ~1 in 4).