Bug: `server.proxy` not working with `@fresh/plugin-vite`

[Hajime-san]

Step to Reproduce

• deno.json

{
  "imports": {
    "vite": "npm:vite@7.1.11",
    "preact": "npm:preact@10.29.1",
    "fresh": "jsr:@fresh/core@2.3.3",
    "@fresh/plugin-vite": "jsr:@fresh/plugin-vite@1.1.2"
  },
  "nodeModulesDir": "auto",
  "compilerOptions": {
    "jsx": "precompile",
    "jsxImportSource": "preact",
    "jsxImportSourceTypes": "preact"
  },
  "tasks": {
    "start": "deno task proxy & deno task dev",
    "dev": "deno run -REWS --allow-run --allow-ffi --allow-net=127.0.0.1:3000,jsr.io:443 vite --host 127.0.0.1 --port 3000",
    "proxy": "deno run --allow-net=127.0.0.1:8000 proxy.ts"
  }
}

• vite.config.ts

import { defineConfig } from 'vite';
import { fresh } from '@fresh/plugin-vite';

export default defineConfig({
  plugins: [fresh()],
  server: {
    host: '127.0.0.1',
    port: 3000,
    proxy: {
      '/api': 'http://127.0.0.1:8000',
    },
  },
});

• main.ts

import { App } from 'fresh';

export const app = new App()
  .get('/', () => new Response('ok'));

• proxy.ts

Deno.serve({ hostname: '127.0.0.1', port: 8000 }, (req) => {
  const url = new URL(req.url);
  console.log(`proxy ${req.method} ${url.pathname}${url.search}`);
  return Response.json({
    ok: true,
    pathname: url.pathname,
    search: url.search,
  });
});

Expected behaviour

% curl -i 'http://127.0.0.1:3000/api/ping?x=1'
HTTP/1.1 200 OK
content-type: application/json
content-length: 50
date: Fri, 22 May 2026 14:44:50 GMT

{"ok":true,"pathname":"/api/ping","search":"?x=1"}%

Acutual behaviour

% curl -i 'http://127.0.0.1:3000/api/ping?x=1'
HTTP/1.1 404
Vary: Origin
content-type: text/plain;charset=UTF-8
Date: Fri, 22 May 2026 14:41:30 GMT
Connection: keep-alive
Keep-Alive: timeout=5
Transfer-Encoding: chunked