Add scaling Alien Grunt boss waves and native simulation; publish Web release

scripts/player.gd

@@ -6,6 +6,7 @@ var damage_feedback: CanvasLayer
 const DamageFeedback = preload("res://scripts/damage_feedback.gd")
 const MAX_HP := 100.0
 var hp := MAX_HP
+var invulnerable := false # only enabled by the explicit native boss simulation flag
 var _regen_elapsed := 0.0
 
 ## Discreto: +1 HP per secondo di gioco, mai oltre il massimo o dopo morte.
@@ -215,7 +216,7 @@ func throw_grenade() -> RigidBody3D:
 	return grenade
 
 func take_damage(amount: float) -> void:
-	if death_started or amount <= 0:
+	if death_started or invulnerable or amount <= 0:
 		return
 	hp = maxf(0, hp - amount)
 	if hp <= 0: