follow-up(web-ui): split timeout recovery, timestamps, and version/update UX

[lidge-jun]

Summary

Follow-up split from #109 so the original broad suggestion can be closed without losing the remaining UX work.

Scope

• Timeout/content-loss UX: preserve or surface partial assistant output when a CLI times out or disconnects.
• Message timestamps: show useful sent/received time metadata in the Web UI without adding visual noise.
• Version/update UX: expose the current cli-jaw version and a low-friction update/check path in the UI.

Notes

#109 bundled several independent suggestions. Track the remaining work here as a focused implementation issue.