Desktop app sidebar repeatedly drops sessions (incl. active session); restart no longer recovers

Environment

• Claude Code 2.1.211, desktop app (macOS)
• macOS 26.5.2 (build 25F84)
• Local sessions, single project directory (~/Projects/stack-comp)

Summary

Sessions repeatedly vanish from the desktop app sidebar while remaining fully intact on disk and in the session index. Occurred 5+ times on 2026-07-16 alone, escalating from one dropped session to the entire project's sessions — including the currently active session — no longer listed. Restarting the app, which previously recovered the list, no longer helps.

Timeline (all 2026-07-16)

1. Session "Phase 0 readiness pass and checklist" (created 10:34Z) disappeared from the sidebar shortly after creation. Session was NOT archived, transcript intact on disk.
2. Recovered via workaround: mcp__ccd_session_mgmt__send_message ping into the session — fresh activity re-surfaced it.
3. Recurred twice more the same day; each rescue session created to fix it subsequently also dropped off the sidebar.
4. Escalation: the active session itself stopped appearing in the sidebar while in use.
5. App restart — which previously forced the session list to reload correctly — no longer recovers the missing sessions.

Diagnostics performed

• mcp__ccd_session_mgmt__list_sessions (include_archived): all "missing" sessions ARE present in the index — isArchived: false, correct cwd, correct lastActivityAt. The data layer is consistent; only the sidebar view is wrong.
• Transcripts on disk in ~/.claude/projects/-Users-bard-Projects-stack-comp/ are complete and current (verified content and timestamps).
• Cross-session send_message pings do update lastActivityAt and previously re-surfaced sessions, but no longer reliably do.
• Sessions remain resumable via claude --resume <uuid> from the terminal — the CLI is unaffected; this is a desktop-app sidebar rendering/refresh issue.

Expected

All non-archived sessions for the project appear in the sidebar, including (at minimum) the currently active one.

Actual

Sessions intermittently disappear from the sidebar despite being active/indexed/unarchived; the staleness survives app restarts.

Impact

User loses the only in-app navigation path to their working sessions and must fall back to terminal claude --resume with hand-recovered transcript UUIDs.