fix(network): prevent null multiplayer peer crashes offline/teardown and fix Nakama RPC session validation

scripts/tekton.gd

@@ -311,7 +311,7 @@ func on_thrown_landing(attacker: Node = null, intensity: float = 1.0):
 	
 	# Disable movement/interaction logic temporarily
 	var controller = get_node_or_null("TektonController")
-	if controller and controller.get("timer"):
+	if controller and is_instance_valid(controller) and controller.get("timer") and is_instance_valid(controller.timer):
 		controller.timer.stop()
 	
 	# Visual Shrink
@@ -329,7 +329,7 @@ func on_thrown_landing(attacker: Node = null, intensity: float = 1.0):
 			t.tween_property(mesh, "scale", base_scale * 0.5, 0.2).set_ease(Tween.EASE_OUT).set_trans(Tween.TRANS_BACK)
 	
 	# Spawn tiles (as requested "tekton will spawn a tiles around that floor also")
-	if is_multiplayer_authority():
+	if is_inside_tree() and is_multiplayer_authority():
 		spawn_tiles_around(int(8 * intensity))
 	
 	# Floor Freeze (Visual/Instant - Run on all clients locally)
@@ -341,7 +341,12 @@ func on_thrown_landing(attacker: Node = null, intensity: float = 1.0):
 		temporarily_change_floor(current_position, 1, 6, 3.0)
 
 	# Wait 3.0 seconds
-	await get_tree().create_timer(3.0).timeout
+	var tree = get_tree() if is_inside_tree() else null
+	if tree:
+		await tree.create_timer(3.0).timeout
+	else:
+		is_recovering = false
+		return
 	
 	# Grow back
 	for i in range(mesh_cache.size()):
@@ -355,7 +360,7 @@ func on_thrown_landing(attacker: Node = null, intensity: float = 1.0):
 	
 	# Resume AI
 	if not is_multiplayer_authority() or not is_carried:
-		if controller and controller.has_method("_start_timer"):
+		if controller and is_instance_valid(controller) and controller.has_method("_start_timer"):
 			controller._start_timer()