Stand down when the portal revokes this instance

The connector treats close code 4410 from the hub as final: it stops
dialling, keeps cloud.json so a new claim code replaces it, and reports
revoked in /cloud/status, which Settings → Remote access shows as Removed
at the portal. Enrolling again, or a restart, brings the link back. An
older hub still answers 403 and the link keeps retrying as before.

frontend/src/components/UserSettings/RemoteAccess.tsx

@@ -36,6 +36,7 @@ type CloudStatus = {
   instance_id: string | null
   last_error: string | null
   connected_since: number | null
+  revoked: boolean
 }
 
 /**
@@ -167,11 +168,20 @@ export function RemoteAccess() {
             <div className="flex flex-col gap-4">
               <dl className="grid gap-3 sm:grid-cols-2">
                 <Field label="Status">
-                  {status.connected
-                    ? "Connected"
-                    : status.last_error
-                      ? `Reconnecting — ${status.last_error}`
-                      : "Reconnecting…"}
+                  {status.connected ? (
+                    "Connected"
+                  ) : status.revoked ? (
+                    <>
+                      Removed at the portal
+                      <span className="mt-1 block text-xs text-muted-foreground">
+                        Connect with a new code to restore remote access.
+                      </span>
+                    </>
+                  ) : status.last_error ? (
+                    `Reconnecting — ${status.last_error}`
+                  ) : (
+                    "Reconnecting…"
+                  )}
                 </Field>
                 <Field label="Portal">{status.portal_url ?? "—"}</Field>
                 <Field label="Acting as">