Add movement constants for pigs and switch deceleration to per-axis friction so creatures stop naturally. Extend wander boost duration for smoother behavior.
Update PhysicalSystem and SpeedSystem to operate on entt::registry
instead of individual components. Add TickVelocity for server creatures
so movement is calculated per tick without frame delta time. LocalPlayer
now implements its own client-side physics with collision detection.
Move per-axis collision detection and move distance calculation to new
PhysicalSystem. Move SpeedSystem implementation from inline header to
separate .cpp file. Add const accessors to Entity. Replace inline AABB
helper with HitboxManager registration of player hitbox using new
PLAYER_SIZE constant. Remove obsolete members and functions from
ClientPlayer.