Persist the user's last active workspace and navigate directly to it
on cold start instead of always landing on the open-project screen.
- Unified bootstrap into one cross-platform wait step after
platform-specific connection setup
- Store-level wait with workspace preference: preferred host online
resolves immediately, grace period if a different host connects
first, bounded 5s timeout for unreachable hosts
- index.tsx is fully declarative — reads resolved target from context,
no useEffect/promises/refs/timers