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/GuzzleHttp/Psr7/DroppingStream.php

@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace GuzzleHttp\Psr7;
+
+use Psr\Http\Message\StreamInterface;
+
+/**
+ * Stream decorator that begins dropping data once the size of the underlying
+ * stream becomes too full.
+ */
+final class DroppingStream implements StreamInterface
+{
+    use StreamDecoratorTrait;
+
+    /** @var int */
+    private $maxLength;
+
+    /** @var StreamInterface */
+    private $stream;
+
+    /**
+     * @param StreamInterface $stream    Underlying stream to decorate.
+     * @param int             $maxLength Maximum size before dropping data.
+     */
+    public function __construct(StreamInterface $stream, int $maxLength)
+    {
+        $this->stream = $stream;
+        $this->maxLength = $maxLength;
+    }
+
+    public function write($string): int
+    {
+        $diff = $this->maxLength - $this->stream->getSize();
+
+        // Begin returning 0 when the underlying stream is too large.
+        if ($diff <= 0) {
+            return 0;
+        }
+
+        // Write the stream or a subset of the stream if needed.
+        if (strlen($string) < $diff) {
+            return $this->stream->write($string);
+        }
+
+        return $this->stream->write(substr($string, 0, $diff));
+    }
+}