feat(multiplayer): handle planned shutdowns on clients

Game/scripts/lobby.gd

@@ -27,6 +27,7 @@ func _ready() -> void:
 	MatchNet.player_left.connect(_on_roster_changed)
 	MatchNet.player_state_changed.connect(_on_roster_changed)
 	MatchNet.rejected.connect(_on_rejected)
+	MatchNet.server_shutdown.connect(_on_server_shutdown)
 	NetworkManager.disconnected_from_server.connect(_on_disconnected_from_server)
 
 	# The server process is never a roster member (§1.1 decision 2) — it
@@ -61,6 +62,10 @@ func _on_rejected(reason: String) -> void:
 	_status_label.text = "Connection rejected: %s" % reason
 
 
+func _on_server_shutdown(reason: String) -> void:
+	_status_label.text = "Server closed: %s" % reason
+
+
 func _on_disconnected_from_server() -> void:
 	get_tree().change_scene_to_file(ScenePaths.MAIN_MENU)
 

Game/scripts/match_net.gd

@@ -53,6 +53,7 @@ class PlayerInfo:
 
 var roster: Dictionary = {}   # peer_id (int) -> PlayerInfo. Never contains peer 1 (the server; §1.1 decision 2 — dedicated servers are never a player).
 var local_player_name := "Player"
+var last_server_shutdown_reason := ""
 # Set by the assignment connection path. Direct-IP/community-server joins keep
 # this empty for backwards compatibility; allocated matches carry the opaque
 # signed authorisation in hello rather than putting it in the endpoint URL.
@@ -80,6 +81,7 @@ func _ready() -> void:
 
 func _on_connected_to_server() -> void:
 	roster.clear()
+	last_server_shutdown_reason = ""
 	if _auto_hello:
 		_hello.rpc_id(1, NetCodec.PROTOCOL_VERSION, SimConstants.TICK_HZ, local_player_name, join_authorisation)
 
@@ -511,7 +513,8 @@ func _rejected(reason: String) -> void:
 
 @rpc("authority", "call_remote", "reliable")
 func _server_shutdown(reason: String) -> void:
-	server_shutdown.emit(_sanitize_shutdown_reason(reason))
+	last_server_shutdown_reason = _sanitize_shutdown_reason(reason)
+	server_shutdown.emit(last_server_shutdown_reason)
 
 
 @rpc("authority", "call_remote", "reliable")

Game/scripts/networked_match.gd

@@ -321,6 +321,7 @@ var _max_spectators := -1
 var _last_emitted_countdown := -1
 var _in_overtime := false
 var _match_over := false
+var _planned_server_shutdown := false
 # Dedicated-export smoke hook (task 6.2). It is parsed only by the authoritative
 # server, cannot be triggered by an RPC, and defaults to disabled.
 var _smoke_force_goal_tick := -1
@@ -391,6 +392,7 @@ func _ready() -> void:
 		# is not connected" errors per run — it only ever left because a test
 		# timer happened to fire.
 		NetworkManager.disconnected_from_server.connect(_on_disconnected_from_server)
+		MatchNet.server_shutdown.connect(_on_server_shutdown)
 		_request_match_config_until_received()
 
 
@@ -994,12 +996,23 @@ func _broadcast_clock_state() -> void:
 
 
 func _on_disconnected_from_server() -> void:
+	if _planned_server_shutdown:
+		return
 	# Deferred: this arrives from inside NetworkManager's poll, and gotcha 27
 	# requires change_scene_to_file never run synchronously from a callback
 	# mid-traversal.
 	get_tree().change_scene_to_file.call_deferred(ScenePaths.MAIN_MENU)
 
 
+func _on_server_shutdown(reason: String) -> void:
+	if multiplayer.is_server() or _planned_server_shutdown:
+		return
+	_planned_server_shutdown = true
+	print("NetworkedMatch: server shutdown notice: %s" % reason)
+	NetworkManager.shutdown()
+	get_tree().change_scene_to_file.call_deferred(ScenePaths.LOBBY)
+
+
 func _on_match_bootstrap_received(state: int, at_tick: int, new_score: Dictionary, end_tick: int, clock_running: bool, reset_gen: int, remaining_ticks: int) -> void:
 	score = new_score.duplicate()
 	score_changed.emit(score.duplicate())

Game/tests/cases/test_match_net.gd

@@ -49,6 +49,7 @@ func test_server_shutdown_message_is_bounded_and_emitted() -> void:
 	instance._server_shutdown("  planned maintenance " + "x".repeat(200))
 	instance.server_shutdown.disconnect(callback)
 	assert_eq(received[0].length(), 96, "shutdown reason is bounded before presentation")
+	assert_eq(instance.last_server_shutdown_reason.length(), 96, "bounded shutdown reason is retained for UI")
 
 
 func test_reservation_reclaim_requires_stable_identity() -> void: