LaneConsolePane kept handle/cwd/prompt/runHistory in local state that was
never reset when the laneId prop changed, so selecting another lane swapped
the header and detail panel while the terminal stayed attached to the
previous lane's tmux session.
Reset the pane on lane switch and re-attach immediately to the new lane's
live run from GET /api/run when it has one, falling back to that lane's
setup form when it does not. `lanes`/`activeRuns` are read through a ref so
the page's 5s poll cannot wipe a half-typed prompt.
nntrivi2001
37adf983e3