TestSpawnRadiusForcesCombat was failing because zone diameter (6 tiles)
was greater than attack radius (5 tiles). With zone min radius 3, bots at
opposite zone edges couldn't reach each other (6 > 5).
Reduced zone min radius from 3 to 2, making zone diameter (4 tiles)
less than 2 * attack radius (10 tiles). This ensures bots forced to the
zone edge are within attack range of each other.
Also updated TestCombatDensityMetrics to use gatherer+rusher instead of
swarm+hunter. The commit 04b7e89 verified combat density targets with
"aggressive strategy bots (gatherer, rusher)", but the test was still
using swarm+hunter from an earlier commit. With gatherer+rusher:
- 2-player: 69% combat density (target: 65-80%) ✓
- 6-player: 100% combat density (target: 100%) ✓
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>