Fix remote server token recovery

[firewalker06]

Summary

• show a Remote token required recovery card on the active server error screen when a peer rejects broker credentials and this browser has no saved peer token
• reuse the existing token save form so switching to a token-protected server no longer strands the user without a re-auth path
• improve small-screen server row layout by moving remote server actions into a full-width grid row

Follow-up for #42 / #41 before v0.6.1.

Verification

• git diff --check
• node --check lib/hq/remote_ui/assets/app.js
• ruby -c test/remote_server_test.rb

Full local Ruby tests remain blocked in this shell by the previously observed Ruby/Bundler path issue.