feat: 多班级版班级管理系统 v2.0

技术栈：Go (Gin + GORM) + PHP + MySQL 5.7 + Redis

主要功能：
- 多班级完全隔离（class_id 贯穿全系统）
- 后端从 Python FastAPI 重写为 Go Gin（端口 56789）
- 超级管理员独立登录（env 配置路径，默认账密 admin/Admin123）
- 科任老师/课代表新角色
- 课代表作业管理页面
- 排行榜分项排行（操行分/考勤/作业）
- 角色加减分上下限由班主任配置
- 家长改密功能（可开关）
- 班级角色按需开关
- 宿舍号格式：南0-000
- 周度/月度重置功能
- MySQL 5.7 兼容
- Nginx 反向代理部署

开发者: Canglan
版权归属: Sea Network Technology Studio
许可证: Apache License 2.0

frontend/api/execute_upgrade.php

@@ -0,0 +1,104 @@
+<?php
+/**
+ * 执行单个升级步骤（代理至后端 API）
+ */
+require_once __DIR__ . '/../config.php';
+
+header('Content-Type: application/json; charset=utf-8');
+
+// 验证登录和权限（admin 班主任 或 super_admin）
+if (!isset($_SESSION['user_id']) || !in_array($_SESSION['user_type'], ['admin', 'super_admin'])) {
+    http_response_code(401);
+    echo json_encode(['success' => false, 'error' => '未授权']);
+    exit();
+}
+
+$userType = $_SESSION['user_type'];
+$role = $_SESSION['role'] ?? '';
+if ($userType === 'admin' && $role !== '班主任') {
+    http_response_code(403);
+    echo json_encode(['success' => false, 'error' => '权限不足']);
+    exit();
+}
+
+// 只接受 POST
+if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
+    http_response_code(400);
+    echo json_encode(['success' => false, 'error' => '无效请求']);
+    exit();
+}
+
+$input = json_decode(file_get_contents('php://input'), true);
+$stepVersion = $input['version'] ?? '';
+if (empty($stepVersion)) {
+    http_response_code(400);
+    echo json_encode(['success' => false, 'error' => '缺少版本号参数']);
+    exit();
+}
+
+// 从 session 获取 JWT token
+$token = $_SESSION['jwt_token'] ?? '';
+if (empty($token)) {
+    http_response_code(401);
+    echo json_encode(['success' => false, 'error' => '会话已过期，请重新登录']);
+    exit();
+}
+
+// 调用后端 API
+$apiUrl = API_BASE_URL . '/api/upgrade/step';
+
+$ch = curl_init();
+curl_setopt_array($ch, [
+    CURLOPT_URL => $apiUrl,
+    CURLOPT_RETURNTRANSFER => true,
+    CURLOPT_POST => true,
+    CURLOPT_POSTFIELDS => json_encode(['version' => $stepVersion]),
+    CURLOPT_TIMEOUT => API_TIMEOUT,
+    CURLOPT_HTTPHEADER => [
+        'Authorization: Bearer ' . $token,
+        'Content-Type: application/json'
+    ],
+    CURLOPT_SSL_VERIFYPEER => true,
+    CURLOPT_SSL_VERIFYHOST => 2
+]);
+
+$apiResponse = curl_exec($ch);
+$httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+curl_close($ch);
+
+if (empty($apiResponse)) {
+    http_response_code(500);
+    echo json_encode([
+        'success' => false,
+        'version' => $stepVersion,
+        'error' => '无法连接升级服务'
+    ]);
+    exit();
+}
+
+$result = json_decode($apiResponse, true);
+if (!$result) {
+    http_response_code(500);
+    echo json_encode([
+        'success' => false,
+        'version' => $stepVersion,
+        'error' => '升级服务返回数据格式错误'
+    ]);
+    exit();
+}
+
+// 后端返回非200或 success=false 时，提取实际错误信息
+if ($httpCode !== 200 || !isset($result['success']) || !$result['success']) {
+    $errorMsg = $result['message'] ?? ($result['error'] ?? '升级失败');
+    http_response_code(500);
+    echo json_encode([
+        'success' => false,
+        'version' => $stepVersion,
+        'error' => $errorMsg
+    ]);
+    exit();
+}
+
+// 转发后端返回的数据
+$data = $result['data'] ?? [];
+echo json_encode($data);