feat: implement weapon framework, hitscan logic, and player movement controller with state management

weapons/projectile.gd

@@ -9,6 +9,7 @@ var owner_player: CharacterBody3D
 var falloff_start: float = 10.0
 var min_damage: float = 5.0
 var drop_gravity: float = 0.0 # For arc projectiles (nailgun might have slight drop, plasma none)
+var impact_type: String = "bullet"
 
 var logical_source = null
 var _previous_position: Vector3
@@ -58,6 +59,8 @@ func _on_hit(result: Dictionary) -> void:
 		
 	if result.collider.has_method("take_damage"):
 		result.collider.take_damage(final_damage, result.position, owner_player)
+	else:
+		var size = 0.4 if impact_type == "plasma" else 0.15
+		ImpactSpawner.spawn(get_tree(), impact_type, result.position, result.normal, size)
 		
-	# Spawn impact effect? Not needed yet for prototype.
 	queue_free()