MRBS 1.12.2 等保2.0二级整改完整提交

包含：登录失败锁定、90天密码有效期、30分钟会话超时、
强制改密、登录审计日志、屏幕水印、企业背景图、
备案信息固定底部、favicon、JS空集合保护、
会话过期体验优化（403 JSON）、display_errors 关闭、
固定 key 根治 Integrity check failed 等全部改动

注意：config.inc.php/.htaccess/.user.ini 含敏感信息，
通过 .gitignore 排除，勿推送到公开仓库。

lib/MRBS/Calendar/CalendarMultimonth.php

@@ -0,0 +1,38 @@
+<?php
+declare(strict_types=1);
+namespace MRBS\Calendar;
+
+use MRBS\DateTime;
+use MRBS\Exception;
+
+abstract class CalendarMultimonth extends Calendar
+{
+  protected $n_months;
+
+  public function __construct(string $view, int $view_all, int $year, int $month, int $day, int $area_id, int $room_id)
+  {
+    global $year_start;
+
+    parent::__construct($view, $view_all, $year, $month, $day, $area_id, $room_id);
+
+    if ($view === 'year')
+    {
+      $this->n_months = MONTHS_PER_YEAR;
+    }
+    else
+    {
+      throw new Exception("Invalid view: '$view'");
+    }
+
+    // Get the start and end dates
+    $this->start_date = (new DateTime())->setDate($this->year, $this->month, 1);
+    $this->start_date->setMonthYearStart($year_start);
+    $this->start_date->setStartFirstSlot();
+
+    $this->end_date = clone $this->start_date;
+    $this->end_date->modify('+' . $this->n_months . ' month');
+    $this->end_date->modify('-1 day');
+    $this->end_date->setEndLastSlot();
+  }
+
+}