The terminal drawer was flickering closed immediately after opening because
the spawned shell process exited with code 1, triggering handleExited →
closeTerminal → onClose which unmounted the entire drawer within ~500ms.
- Stop auto-closing the drawer on process exit so users can see error output
- Extract URL param building into testable buildWorkspaceSyncParams function
that correctly includes terminal state, preventing param stripping on navigation
- Add 21 tests covering terminal param preservation across navigation scenarios
