feat: 实现时间流动完整逻辑并同步 HUD 显示

- TimeSystem 支持月/年进位，仅游戏场景推进
- HUD 时间标签订阅 day_passed 实时更新
- 新游戏时重置年月日

src/UI/HUD/top_bar_hud.gd

@@ -10,7 +10,12 @@ func _ready() -> void:
 	for i in SPEED_BUTTONS.size():
 		var btn: Button = $HBoxContainer/SpeedGroup.get_node(SPEED_BUTTONS[i])
 		btn.button_up.connect(_on_speed_button_up.bind(i))
+	TimeSystem.day_passed.connect(_on_day_passed)
 	_update_speed_ui()
+	$HBoxContainer/Value_Time.text = TimeSystem.get_date_text()
+
+func _on_day_passed(_year: int, _month: int, _day: int) -> void:
+	$HBoxContainer/Value_Time.text = TimeSystem.get_date_text()
 
 func _on_button_return_button_up() -> void:
 	sign_return_mainmenu.emit()