fix(handler): 统一错误处理并替换Next.js重写为路由处理器

- 将所有handler中的Fail函数调用替换为FailError以统一错误处理
- 添加FailError函数实现统一的错误日志记录和响应格式
- 移除Next.js配置中的rewrites并实现统一的API路由代理处理器
- 新增路由处理器支持长连接和大文件上传场景的代理转发
- 更新错误处理逻辑避免将内部错误详情暴露给前端用户

web/next.config.ts

@@ -1,6 +1,5 @@
 import type { NextConfig } from "next";
 import { PHASE_DEVELOPMENT_SERVER } from "next/constants";
-import { loadEnvConfig } from "@next/env";
 import { readFileSync } from "node:fs";
 import { fileURLToPath } from "node:url";
 import { dirname, resolve } from "node:path";
@@ -12,8 +11,6 @@ const localChangelog = readFileSync(resolve(webDir, "../CHANGELOG.md"), "utf8");
 
 export default function nextConfig(phase: string): NextConfig {
   const isDev = phase === PHASE_DEVELOPMENT_SERVER;
-  loadEnvConfig(resolve(webDir, ".."), isDev, undefined, true);
-  const apiBaseUrl = process.env.API_BASE_URL || "http://127.0.0.1:8080";
   const releases = parseChangelog(localChangelog);
 
   return {
@@ -25,8 +22,5 @@ export default function nextConfig(phase: string): NextConfig {
       NEXT_PUBLIC_APP_VERSION: localVersion,
       NEXT_PUBLIC_APP_RELEASES: JSON.stringify(releases),
     },
-    async rewrites() {
-      return [{ source: "/api/:path*", destination: `${apiBaseUrl}/api/:path*` }];
-    },
   };
 }