feat: 新增api接口

Co-authored-by: Copilot <copilot@github.com>

server/api/auth/register.post.ts

@@ -0,0 +1,66 @@
+// server/api/auth/register.post.ts
+import type { UserRegisterRequest, UserRegisterResult } from "#shared/types";
+import {
+  createUpstreamErrorResponse,
+  createErrorResponse,
+  createSuccessResponse,
+  newApiFetch
+} from "../../utils";
+
+/**
+ * 允许从请求体透传给上游的字段列表
+ * 只有在这里声明过的字段才会被转发，其余字段一律丢弃，防止参数污染
+ * 与 NewAPI 文档字段保持一致
+ */
+const REGISTER_FIELDS = [
+  "username",
+  "password",
+  "email",
+  "verification_code",
+  "aff_code"
+] as const satisfies ReadonlyArray<keyof UserRegisterRequest>;
+
+/**
+ * POST /api/auth/register
+ *
+ * 注册流程：
+ *  1. 解析并校验前端传来的 JSON 请求体
+ *  2. 从请求体里只挑出文档允许的字段组装 payload
+ *  3. 通过 newApiFetch 转发到上游 NewAPI 注册接口
+ *  4. 将上游结果统一包装为 ApiResponse 格式返回给前端
+ */
+export default defineEventHandler(async (event) => {
+  // 读取并反序列化请求体；如果前端没有传 body，readBody 会返回 null
+  const requestBody = await readBody<Partial<UserRegisterRequest> | null>(
+    event
+  );
+
+  // 防御性校验：请求体只能是 JSON 对象或空，不接受字符串/数字等原始值
+  if (requestBody !== null && typeof requestBody !== "object") {
+    return createErrorResponse(400, "请求体必须是 JSON 对象");
+  }
+
+  // 白名单过滤：只保留文档里声明的字段，且必须是字符串类型
+  const payload: UserRegisterRequest = {};
+  for (const field of REGISTER_FIELDS) {
+    const value = requestBody?.[field];
+    if (typeof value === "string") {
+      payload[field] = value;
+    }
+  }
+
+  try {
+    const result = await newApiFetch<UserRegisterResult>("/api/user/register", {
+      method: "POST",
+      body: payload,
+      headers: {
+        "Content-Type": "application/json"
+      }
+    });
+
+    // 上游成功
+    return createSuccessResponse(result, "注册成功");
+  } catch (error) {
+    return createUpstreamErrorResponse(error, "注册失败");
+  }
+});