♻️ refactor(syzoj-header): restructure navigation menu and upgrade LLM model

- Remove "来源/分类" (category.php) link from main navigation
- Relocate "cppreference" to end of menu, after contest-related items
- Add conditional "AI 聊天" section using `$OJ_AI_HTML` variable
- Update LLM model from `MiniMax-M2.7` to `MiniMax-M3` in db_info.inc.php
- Fix trailing whitespace in header.php template

web/include/db_info.inc.php

@@ -149,7 +149,7 @@ static $OJ_MENU_NEWS=true;
 static $OJ_LLM_ENABLED=false;              // 总开关，设为true开启AI点评
 static $OJ_LLM_API_URL="https://api.minimaxi.com/anthropic/v1/messages"; // API地址（MiniMax Anthropic兼容格式）
 static $OJ_LLM_API_KEY="sk-cp-w571CJpA_6WP5P6b_xGVbjOqXOGBWTQsiNY9xxAPambouIhD7ic3GHIoWce0ON_Y7Q0rVLzBWtgwwS8cQVUxS1guBxYkPJoJ33q0jEcx0Qei60bx5La4fB4";                 // 填入你的MiniMax API Key
-static $OJ_LLM_MODEL="MiniMax-M2.7";       // 模型名称，如 MiniMax-M2.7 / MiniMax-M2.5 / MiniMax-M2.5-highspeed
+static $OJ_LLM_MODEL="MiniMax-M3";       // 模型名称，如 MiniMax-M3 / MiniMax-M2.7 / MiniMax-M2.5 / MiniMax-M2.5-highspeed
 static $OJ_LLM_MAX_TOKENS=65536;            // 最大输出token数
 static $OJ_LLM_TIMEOUT=60;                 // 请求超时（秒），LLM响应较慢建议60秒
 static $OJ_LLM_SYSTEM_PROMPT="";           // 自定义系统prompt，留空使用内置默认

web/template/syzoj/header.php

@@ -216,20 +216,17 @@ a.label:hover {
             <!-- 问题 -->
             <a class="item <?php if ($url=="problemset.php") echo "active";?>"
                 href="<?php echo $path_fix?>problemset.php"><i class="list icon"></i><?php echo $MSG_PROBLEMS?> </a>
-            <!-- 来源/分类 -->
-            <a class="item <?php if ($url=="category.php") echo "active";?>"
-                href="<?php echo $path_fix?>category.php"><i class="globe icon"></i><?php echo $MSG_SOURCE?></a>
             <!-- 竞赛/作业 -->
             <a class="item <?php if ($url=="contest.php") echo "active";?>" href="<?php echo $path_fix?>contest.php<?php if(isset($_SESSION[$OJ_NAME."_user_id"])) echo "?my" ?>" ><i
                     class="trophy icon"></i> <?php echo $MSG_CONTEST?></a>
             <!-- 状态 -->
             <a class="item <?php if ($url=="status.php") echo "active";?>" href="<?php echo $path_fix?>status.php"><i
                     class="tasks icon"></i><?php echo $MSG_STATUS?></a>
-            <!-- cppreference -->
+            <!-- AI 聊天 -->
-            <a class="item <?php if ($url=="cppreference.php") echo "active";?>" 
+            <?php
-                href="cppreference.php">
+              if(isset($OJ_AI_HTML)&&$OJ_AI_HTML) echo $OJ_AI_HTML;
-                <i class="help icon"></i><?php echo $MSG_CPPREFRENCE?>
+            ?>
-            </a>
+            <!-- 文档 -->
             <a class="item <?php if ($url=="docs.php") echo "active";?>"
                 href="<?php echo $path_fix?>docs.php"><i class="book icon"></i> 文档</a>
             <!-- 排名 -->
@@ -251,9 +248,6 @@ a.label:hover {
 
             }
                 ?>
-            <?php if( isset($_GET['cid']) && intval($_GET['cid'])>0 ){
-                $cid=intval($_GET['cid']);
-            ?>
             <a id="" class="item" href="<?php echo $path_fix?>contest.php" ><i class="arrow left icon"></i><?php echo $MSG_CONTEST.$MSG_LIST?></a>
             <a id="" class="item active" href="<?php echo $path_fix?>contest.php?cid=<?php echo $cid?>" ><i class="list icon"></i><?php echo $MSG_PROBLEMS.$MSG_LIST?></a>
             <a id="" class="item active" href="<?php echo $path_fix?>status.php?cid=<?php echo $cid?>" ><i class="tasks icon"></i><?php echo $MSG_STATUS.$MSG_LIST?></a>
@@ -267,6 +261,14 @@ a.label:hover {
                             <a id="" class="item active" href="<?php echo $path_fix?>conteststatistics.php?cid=<?php echo $cid?>" ><i class="eye icon"></i><?php echo $MSG_STATISTICS?></a>
                     <?php }  ?>
             <?php }  ?>
+            
+            <!-- cppreference（菜单最后） -->
+            <a class="item <?php if ($url=="cppreference.php") echo "active";?>"
+                href="cppreference.php"><i class="help icon"></i><?php echo $MSG_CPPREFRENCE?></a>
+            <?php if( isset($_GET['cid']) && intval($_GET['cid'])>0 ){
+                $cid=intval($_GET['cid']);
+            ?>
+            
             <?php echo $sql_news_menu_result_html; ?>
             <div class="right menu">
                 <?php if(isset($_SESSION[$OJ_NAME.'_'.'user_id'])) { ?>