feat: implement walking and killable enemy dummy entities and player movement controller base

entities/walking_dummy.gd

@@ -11,6 +11,7 @@ var max_shield: float = 100.0
 var shield: float = 100.0
 
 var is_dead: bool = false
+var time_since_last_damage: float = 0.0
 var recent_attackers: Dictionary = {} # attacker_id: timestamp
 var ragdoll_instance: Node3D = null
 var pending_impulse: Vector3 = Vector3.ZERO
@@ -51,6 +52,14 @@ func _physics_process(delta: float) -> void:
 	if is_dead:
 		return
 		
+	# Shield recharge logic
+	time_since_last_damage += delta
+	if time_since_last_damage >= 5.0 and shield < max_shield:
+		shield += 20.0 * delta
+		if shield > max_shield:
+			shield = max_shield
+		_update_label()
+		
 	# Basic gravity
 	if not is_on_floor():
 		velocity.y -= 9.8 * delta
@@ -98,6 +107,8 @@ func take_damage(amount: float, hit_position: Vector3, source: Node = null, impu
 	if attacker_id != 0:
 		recent_attackers[attacker_id] = Time.get_ticks_msec() / 1000.0
 		
+	time_since_last_damage = 0.0
+		
 	var dmg_taken = amount
 	if shield > 0:
 		if shield >= amount:
@@ -109,6 +120,8 @@ func take_damage(amount: float, hit_position: Vector3, source: Node = null, impu
 			
 	if amount > 0:
 		health -= amount
+		if health <= 0:
+			health = 0
 		
 	_update_label()