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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@local/dsh-remote",
-  "version": "0.4.0",
+  "version": "0.5.0",
   "description": "Claude-Desktop-style remote control for DSH: master/slave link, every device's sessions on every device (/r/<device>/), plugin + config sync with opt-in secrets.",
   "private": true,
   "type": "module",