refactor: 引入 apiHandler + ApiError，消除 20 个路由的 try/catch 样板

- 新增 src/lib/api.ts：ApiError 错误类 + apiHandler 统一包装器
- 20 个 API 路由统一使用 apiHandler，删除重复的 try/catch 块
- 验证错误改用 throw new ApiError()，减少嵌套层级
- join/manage 路由的错误码映射改为直接抛出 ApiError
- 删除已无引用的 errorResponse 辅助函数
- 净减 273 行代码

src/app/api/user/favorite/route.ts

@@ -1,11 +1,10 @@
-import { NextRequest, NextResponse } from "next/server";
+import { NextResponse } from "next/server";
 import { prisma } from "@/lib/prisma";
+import { apiHandler, ApiError } from "@/lib/api";
 
-export async function GET(req: NextRequest) {
+export const GET = apiHandler(async (req) => {
   const userId = req.nextUrl.searchParams.get("userId");
-  if (!userId) {
-    return NextResponse.json([]);
-  }
+  if (!userId) return NextResponse.json([]);
 
   const favorites = await prisma.favorite.findMany({
     where: { userId },
@@ -20,19 +19,15 @@ export async function GET(req: NextRequest) {
       createdAt: f.createdAt.toISOString(),
     })),
   );
-}
+});
 
-export async function POST(req: NextRequest) {
+export const POST = apiHandler(async (req) => {
   const { userId, restaurant } = await req.json();
 
-  if (!userId || !restaurant) {
-    return NextResponse.json({ error: "缺少必要字段" }, { status: 400 });
-  }
+  if (!userId || !restaurant) throw new ApiError("缺少必要字段");
 
   const user = await prisma.user.findUnique({ where: { id: userId } });
-  if (!user) {
-    return NextResponse.json({ error: "请先设置个人资料" }, { status: 404 });
-  }
+  if (!user) throw new ApiError("请先设置个人资料", 404);
 
   const existing = await prisma.favorite.findFirst({
     where: {
@@ -53,20 +48,16 @@ export async function POST(req: NextRequest) {
   });
 
   return NextResponse.json({ id: fav.id });
-}
+});
 
-export async function DELETE(req: NextRequest) {
+export const DELETE = apiHandler(async (req) => {
   const { userId, favoriteId } = await req.json();
 
-  if (!userId || !favoriteId) {
-    return NextResponse.json({ error: "缺少必要字段" }, { status: 400 });
-  }
+  if (!userId || !favoriteId) throw new ApiError("缺少必要字段");
 
   const fav = await prisma.favorite.findUnique({ where: { id: favoriteId } });
-  if (!fav || fav.userId !== userId) {
-    return NextResponse.json({ error: "收藏不存在" }, { status: 404 });
-  }
+  if (!fav || fav.userId !== userId) throw new ApiError("收藏不存在", 404);
 
   await prisma.favorite.delete({ where: { id: favoriteId } });
   return NextResponse.json({ ok: true });
-}
+});