Server bots and PVE balance pass

Bots

Added class-based server bot AI with a full lifecycle and a managed population.

Improved player AI turret fire control and targeting against enemy ships.

Increased WAR bot counts and kept wreck mass in the field longer.

Balance

Retuned PVE waves and boss difficulty for a steadier ramp.

Spread team spawns and stabilized the minimap and HUD.