fix(transport): use node:https instead of undici (module not exported)

Next.js could not resolve undici as a top-level import even though it
ships internally. Drop that path and call the ORGP endpoint via the
built-in node:https with a per-request Agent(rejectUnauthorized: false).
Adds runtime = nodejs on the route so Node APIs are guaranteed.

app/api/transport/route.ts

@@ -1,11 +1,52 @@
 export const dynamic = 'force-dynamic'
+export const runtime = 'nodejs'
+
 import { NextResponse } from 'next/server'
-import { Agent } from 'undici'
+import * as https from 'node:https'
 
-const ORGP_BASE = 'https://transport.orgp.spb.ru'
+const ORGP_HOST = 'transport.orgp.spb.ru'
 
-// ORGP TLS chain fails default verification in Node — match curl -k behaviour.
-const insecureAgent = new Agent({ connect: { rejectUnauthorized: false } })
+// ORGP TLS chain fails default verification — accept like curl -k for this one host.
+const insecureAgent = new https.Agent({ rejectUnauthorized: false })
+
+interface UpstreamResult {
+  status: number
+  body: string
+}
+
+function postOrgp(path: string, form: string): Promise<UpstreamResult> {
+  return new Promise((resolve, reject) => {
+    const req = https.request(
+      {
+        host: ORGP_HOST,
+        path,
+        method: 'POST',
+        agent: insecureAgent,
+        timeout: 8000,
+        headers: {
+          'X-Requested-With': 'XMLHttpRequest',
+          'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8',
+          'Accept': 'application/json, text/javascript, */*; q=0.01',
+          'Content-Length': Buffer.byteLength(form).toString(),
+        },
+      },
+      (res) => {
+        let data = ''
+        res.setEncoding('utf8')
+        res.on('data', (chunk) => {
+          data += chunk
+        })
+        res.on('end', () => resolve({ status: res.statusCode || 0, body: data }))
+      }
+    )
+    req.on('timeout', () => {
+      req.destroy(new Error('upstream timeout'))
+    })
+    req.on('error', reject)
+    req.write(form)
+    req.end()
+  })
+}
 
 export async function GET(req: Request) {
   const { searchParams } = new URL(req.url)
@@ -14,40 +55,29 @@ export async function GET(req: Request) {
     return NextResponse.json({ error: 'stopId required (digits)' }, { status: 400 })
   }
 
-  const body = new URLSearchParams({
+  const form = new URLSearchParams({
     sEcho: '1',
     iColumns: '5',
     sColumns: 'index,routeNumber,timeToArrive,parkNumber,wheelchair',
     iDisplayStart: '0',
     iDisplayLength: '-1',
     sNames: 'index,routeNumber,timeToArrive,parkNumber,wheelchair',
-  })
+  }).toString()
 
   try {
-    const upstream = await fetch(
-      `${ORGP_BASE}/Portal/transport/stop/${encodeURIComponent(stopId)}/arriving`,
-      {
-        method: 'POST',
-        headers: {
-          'X-Requested-With': 'XMLHttpRequest',
-          'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8',
-          'Accept': 'application/json, text/javascript, */*; q=0.01',
-        },
-        body: body.toString(),
-        cache: 'no-store',
-        // @ts-ignore — undici dispatcher option at runtime
-        dispatcher: insecureAgent,
-      }
+    const { status, body } = await postOrgp(
+      `/Portal/transport/stop/${encodeURIComponent(stopId)}/arriving`,
+      form
     )
 
-    if (!upstream.ok) {
+    if (status !== 200) {
       return NextResponse.json(
-        { error: `upstream_${upstream.status}`, arrivals: [] },
+        { error: `upstream_${status}`, arrivals: [] },
         { status: 502 }
       )
     }
 
-    const data = await upstream.json()
+    const data = JSON.parse(body)
     const arrivals = Array.isArray(data?.aaData)
       ? data.aaData.map((row: any[]) => ({
           route: String(row[1] ?? ''),