Sidebar session list repeatedly goes empty despite session data being intact

Description

The desktop app's left sidebar session list intermittently goes empty — all sessions disappear from the panel — even though the underlying session data is confirmed intact.

Steps observed

• Sidebar showed 20+ sessions, then went empty with no error shown.
• Recurred on two separate occasions: 2026-08-20 and 2026-08-21.

Confirmed NOT data loss

Queried the session store directly both times via the session management API — all sessions (49+, going back to mid-June) were present, none archived, none deleted. The sidebar's fetch/render layer is failing silently while the backend data is fine.

Troubleshooting already tried (did not fix it)

• Reload / hard refresh
• Full quit and relaunch (not just closing the window)
• Checking the workspace/folder filter
• Checking for a stray search term in the sidebar search box

Environment

• Desktop app (Mac)