dsh-remote 0.5.0: node settings, session-cookie edge auth, sign-in popup

- Settings → Remote devices → Node: type master|slave (stored in state, beats
  config role; Restart DSH button under systemd/launchd), origin (read-only:
  own origin / paired master), 'Master has an auth middleware' toggle
- middleware on: a non-DSH answer on the link (login redirect, 401/403, inline
  HTML) raises auth-required; the UI opens <master>/dsh-remote/signin in a popup,
  the user signs in to the proxy, one click hands the proxy session cookie back
  (postMessage, origin-checked, trusted origins only), link retries
- edge mode 'cookie': pasted authentik_proxy_… (or a whole Cookie header),
  rotated proxy cookies persisted back; pair.mjs/install-mac --edge cookie
- connectMaster serialised; a failed attempt never clears a finished link
- tests: cookie seed/mode, HTML login wall; e2e-signin against a fake proxy

deploy/fake-edge.mjs

@@ -37,7 +37,7 @@ const srv = http.createServer((req, res) => {
   }
   const p = http.request({ host: up.hostname, port: up.port, method: req.method, path: req.url, headers: { ...strip(req.headers), host: up.host } }, (r) => {
     const h = { ...r.headers }
-    if (a.setCookie) h['set-cookie'] = [...(h['set-cookie'] || []), a.setCookie]
+    if (a.setCookie) h['set-cookie'] = [a.setCookie, ...(h['set-cookie'] || [])]
     res.writeHead(r.statusCode, h)
     r.pipe(res)
   })