fix: enforce Chinese font for all UI controls

_Core/managers/UIFontManager.gd

@@ -0,0 +1,26 @@
+extends Node
+
+# Enforce a Chinese-capable font for every UI control, including controls
+# constructed dynamically after their scene has loaded.
+const UI_FONT: FontFile = preload("res://assets/fonts/msyh.ttc")
+
+func _enter_tree() -> void:
+	get_tree().node_added.connect(_on_node_added)
+	_apply_font_recursively(get_tree().root)
+
+func _exit_tree() -> void:
+	var node_added_callback := Callable(self, "_on_node_added")
+	if get_tree().node_added.is_connected(node_added_callback):
+		get_tree().node_added.disconnect(node_added_callback)
+
+func _on_node_added(node: Node) -> void:
+	_apply_font_recursively(node)
+
+func _apply_font_recursively(node: Node) -> void:
+	if node is Control:
+		var control := node as Control
+		control.add_theme_font_override(&"font", UI_FONT)
+		if control is RichTextLabel:
+			control.add_theme_font_override(&"normal_font", UI_FONT)
+	for child in node.get_children():
+		_apply_font_recursively(child)