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。

upgrade/60/mysql.sql

@@ -0,0 +1,13 @@
+#
+# Change remaining tables to use utf8mb4 charset instead of the now amibiguous utf8 charset.
+# (utf8 currently defaults to utf8mb3 but in a future release will default to utf8mb4).
+# Reduce the size of keyed fields to avoid bumping into the maximum size for a key.
+
+ALTER TABLE %DB_TBL_PREFIX%zoneinfo
+  CONVERT TO CHARSET utf8mb4 COLLATE utf8mb4_unicode_ci,
+  MODIFY timezone varchar(127) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT '' NOT NULL,
+  MODIFY vtimezone text CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
+
+ALTER TABLE %DB_TBL_PREFIX%sessions
+  CONVERT TO CHARSET utf8mb4 COLLATE utf8mb4_unicode_ci,
+  MODIFY id varchar(191) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL;