fix(multiplayer): gate allocated matches on full roster

Game/scripts/server_boot.gd

@@ -83,6 +83,10 @@ func _ready() -> void:
 			get_tree().quit(1)
 			return
 		_control = ServerControlScript.new()
+		# An allocated process owns exactly the roster issued for this match.
+		# Never let the general-purpose direct-server default (one player) start
+		# an allocated match with only a partial assignment admitted.
+		config.values["min-players"] = required_min_players(true, roster_tokens.size(), int(config.get_value("min-players")))
 		_control.name = "ServerControl"
 		_control.drain_requested.connect(_on_drain_requested)
 		get_tree().root.add_child.call_deferred(_control)
@@ -180,3 +184,9 @@ func _on_drain_requested() -> void:
 	_drain_requested = true
 	MatchNet.admissions_open = false
 	ServerLog.info("server_draining", {"reason": "control_request"})
+
+
+static func required_min_players(allocated: bool, roster_size: int, configured: int) -> int:
+	if allocated and roster_size > 0:
+		return roster_size
+	return configured