feat(hub): one account, several linked nodes

An account links up to MAX_NODES_PER_ACCOUNT node keys (node_keys table)
instead of the one users.pk_node_ed25519; the migration carries each
account's key over and the downgrade keeps the last one linked.
/v1/nodes/auth accepts any linked key, and its token names the key that
won it (nk). PUT /me/node_key adds a key, idempotently, 409 past the
limit; DELETE /me/node_key names the key: a browser session any of its
own, a node only its own. Unlinking a key closes that node's socket and
refuses its tokens at once, on REST and on the socket; the account's other
nodes are untouched. /pubkeys no longer gives a node key to other accounts,
and gives the caller its last linked one, which installed desktop apps read.

The node reports waiting_for_node_key while its key is unlinked and signs
in again as soon as the hub says so, so a key linked again is back within
seconds; unlinking itself signs in first to hold a token naming its key.

Profile -> Linked nodes lists each node (connected, last seen, IP, linked
since, This machine in the desktop app) with Copy and Unlink, and adds a
key by hand. The Node page banner, Create group and the desktop app add
this machine's key instead of replacing another's. Messages that pointed
at Settings -> Link Node point at Profile -> Linked nodes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/app.js b/packages/meshbay-hub/src/meshbay_hub/static/app.js
index ea4cee6..195660c 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/app.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/app.js
@@ -17,7 +17,7 @@ import {
   _storeBundleKey, _loadBundleKey, _clearKeyDB,
   loadAuth, saveAuth, setAuth, setAuthChangeListener, ensureFreshToken, hubFetch,
   refreshAccessToken, logoutOnHub,
-  mirrorBrowserAccess,
+  mirrorBrowserAccess, linkedNodeKeys,
 } from './hub-client.js';
 import { startIdleWatch, markActive } from './idle.js';
 import { GroupPage } from './group-page.js';
@@ -1089,8 +1089,8 @@ function App() {
     if (!user || !platform.capabilities.nodeAdmin) return;
     // A late answer, or a retry, must not land on a session that has changed.
     const current = () => nodeKeyAskedForRef.current === user;
-    const ask = (attempt) => hubFetch(`/v1/users/${user.username}/pubkeys`, { token: user.token })
-      .then(data => { if (current()) setHasNodeKey(Boolean(data.pk_node_ed25519)); })
+    const ask = (attempt) => linkedNodeKeys(user.token)
+      .then(data => { if (current()) setHasNodeKey(Boolean(data.keys && data.keys.length)); })
       .catch(() => {
         if (attempt < 3 && current()) setTimeout(() => ask(attempt + 1), 2000 * attempt);
       });