fix a timing issue where sometimes rtv beam particles won't show

fixed vis
fixed vis during end_of_match
made timer red during boss timer countdown
replaced countdown particle with a newer particle system that uses a logic_timer so that the timer is more accurate
tweaked lighting in first gray area after boss

lighting adjustments after boss
fix the skybox cubes and skybox black box being killed after the boss preventing them from persisting on subsequent rounds
fix the blue groundhog laser attack delay

fix exploitation on level 1 due to a gap in geometry
mark all triggers having to do with door / stage logic to "trigger once" to avoid things such as duplicate timers on level 2 (since level 2 is autotrigger, but you can also trigger manually)
reduce the size of the door timer overlay, and use the new clear overlay
fix the ending sequence with gears where a func_door was not working as intended causing the gears to be clumped in the middle, whereas now the behaviour should be the same as csgo
fix a broken counter on the boss that was preventing boss "phase 2" from enabling, as well as enable two boss attacks that are supposed to happen during phase two (spinning rings and jump / crouch spinning beams)
fix a broken info_particle_system that was not illuminating a beam on the double beam attack
reduce the self-illumiantion amount in the beam particle effect
increase the "smokiness" of the smoke particles
replaced the skybox with the original skybox texture (it was previously an ai-upscaled version to remove the ugly banding on the og skybox, but i think that the reworked one was a little bit too deep blue)
optimize lightmaps a little bit more to reduce artifacts in obvious locations
remove the self-illumation lighting style on phase 1 of the post boss escape sequence, now this area is just normally static-lit, so it should be a little bit easier see

fix bug where humans max health is 175
fix heal overhealing
fix heal to only heal 1 hp every tick
fix fade on level 1 applying globally

fix post boss tp
fix cubemap issue on skybox particles during ending
adjust post process
remove some unused assets

various fixes from initial test

Created ze_grau_p.