feat: add player character script with movement, state, and multiplayer synchronization.

scenes/player.gd

@@ -723,6 +723,7 @@ func _refresh_player_visuals():
 		color_to_apply = Color(1.0, 0.5, 0.5) # Attack Mode (Red Tint)
 	elif is_carrying_tekton or is_knock_mode:
 		color_to_apply = Color(1.0, 1.0, 0.0) # Carrying or Knocking (Yellow)
+		alpha_to_apply = 0.5 # 50% opacity when carrying Tekton
 	elif immunity_timer > 0:
 		color_to_apply = Color(0.5, 1.0, 0.5) # Immunity (Light Green)
 	elif is_invisible:
@@ -754,8 +755,8 @@ func update_rank_visuals(rank: int):
 func _apply_tint_recursive(node: Node, color: Color, alpha: float = 1.0):
 	if node is MeshInstance3D:
 		var mat = StandardMaterial3D.new()
-		mat.albedo_color = color
-		mat.albedo_color.a = alpha
+		mat.albedo_color = Color(color.r, color.g, color.b, alpha)
+		mat.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
 		mat.blend_mode = BaseMaterial3D.BLEND_MODE_MIX
 		mat.cull_mode = BaseMaterial3D.CULL_DISABLED
 		mat.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED