Fixes regression from Tasks 1-2:
1. Run.defaultCwd.test.tsx was failing because LaneConsolePane wasn't
rendering when no lane was selected (in layout-1 with zero lanes).
2. Added fallback rendering of LaneConsolePane in Workspace when
!currentLane, so RunSetup stays reachable on fresh install.
3. Fixed early-return condition in LaneConsolePane to only show
dropdown-only placeholder when showLaneSelector=true && laneId=null
(split-view mode), not in layout-1 mode.
4. Added useEffect to sync cwd state with defaultCwd when it changes
asynchronously from parent.
5. Updated LaneConsolePane tests to reflect correct behavior.
6. Regenerated snapshot to match layout-1 output.
The wsConnected prop was destructured but unused. This restores the
live/offline status pill next to the page title, matching the original
Header function design and consuming the prop properly.