Applied nebula lit shader to "planets" and asteroids
Modified gas giant shader to accept nebula lighting and to be a bit less crappy in general
Fixed raymarching depth sampling perspective distortion
Converted entity materials to new fade shader
Implemented visibility system
Refactored per-instance entity code to run inside monobehavior on entity instances
Created state machine AI for enemy ships with basic patrol and combat routines
Removed legacy AI code (controller item behaviors)
Added automatic trigger group assignment for matched weapons
Created ship collision system
Created shield VFX and colliders