Add unarchive action to session toolbar

[tella-butler]

Summary

• show Unarchive in the archived session toolbar where Add to sidebar appears for non-archived sessions
• route the action through App's existing optimistic unarchive flow
• preserve Add to sidebar behavior and avoid a duplicate archived-session overflow action
• cover archived desktop and non-archived phone action rendering

Checks

• bun test packages/core/opensession-server/src/frontend/components/SessionSidebarAction.test.tsx
• bun run lint
• bun run typecheck
• light-mode capture harness exercised at 1440×900 and 390×844

Started by Kent de Bruin in this OS session

[open-session-os-tella-dev]

🤖 OS review · approve · confidence 5/5

Safe to merge. The PR adds the archived-session Unarchive action in the existing desktop and phone placements, routes it through App's optimistic flow, preserves Add to sidebar, and removes the duplicate overflow action without breaking other callers.

💡 Labels: os-adversarial — deeper two-pass review · os-simplify — quality cleanup pass · os-auto-fix — fix anything outstanding and push until CI passes.
_{Reviewed 831a9fc · GPT-5.6 Sol · earlier reviews collapse above · open session}

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
opensession	Ready	Preview	Aug 28, 2026 3:28pm