Desktop app: window freezes on a gray loading screen overnight while sessions keep running

Overnight, the app's window freezes on the gray loading screen. The sessions keep working in the background, but nothing is visible: no sidebar, no conversation, no way to see what ran or step in. You start an 8-hour job at midnight and wake up to gray boxes, with no idea whether it finished, stalled, or is waiting on you. The only way to get the window back is quitting, which stops every running session. This has happened on several overnight runs. Same stuck-after-reload behavior as #97259.

Cost: the run may be fine, but you can't see it or use it, so the morning goes to quitting, restarting, and piecing together what happened.

Fix: let the window recover without quitting, so it reconnects to the sessions still running.

Windows 11, desktop app, Code tab, Claude Code 2.1.300.