The desktop journal synchronously read, parsed, cloned, and rewrote one
aggregate localStorage value while streamed turns were repainting. Large
tool results and multi-session state could therefore block the renderer and
leave the app unresponsive, while the existing macOS diagnostic path lacked
a real native hide/restore regression check.
Store bounded recovery projections under per-session keys, migrate legacy v1
data once, isolate quota and storage failures, and preserve the newest
recoverable tail without allowing oversized writes to replace valid state.
Add a real Electron/CDP macOS-arm64 A/B harness with native visibility control,
renderer heartbeat and Settings/composer/transcript checks, plus focused
regressions. Keep bulk tool payloads, diagnostics, and the existing recovery
merge behavior out of the hot path.
Fixes#63047
Eugeniusz Gilewski