docs: fix api-reference with proxy (#7952)

www/apps/api-reference/app/api/download/[area]/route.ts

@@ -1,29 +0,0 @@
-import { existsSync, readFileSync } from "fs"
-import { NextResponse } from "next/server"
-import path from "path"
-
-type DownloadParams = {
-  params: {
-    area: string
-  }
-}
-
-export function GET(request: Request, { params }: DownloadParams) {
-  const { area } = params
-  const filePath = path.join(process.cwd(), "specs", area, "openapi.full.yaml")
-
-  if (!existsSync(filePath)) {
-    return new NextResponse(null, {
-      status: 404,
-    })
-  }
-
-  const fileContent = readFileSync(filePath)
-
-  return new Response(fileContent, {
-    headers: {
-      "Content-Type": "application/x-yaml",
-      "Content-Disposition": `attachment; filename="openapi.yaml"`,
-    },
-  })
-}