Added credits display to trade screen
Fixed bug in inventory screen where a failed drag from a cargo bay would make the item disappear until a refresh is triggered
Changed behavior of Escape key to exit menu if a menu is open
Fixed zone map gravity isolines to correctly track maximum gravity depth
Refactored orbit and planet data to replace reactive variables with regular ones
Improved volumetric flow performance by orders of magnitude
Cleaned up old raymarching support code
Moved asteroid height calculation to vertex shader
Manual culling for asteroid field render update
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
