The Workspace page rendered `ConsoleArea` from two sites, picked by
`currentLane`. Every flip of that value unmounted the whole console
subtree and mounted it again at the other site: the terminal died, the
run history went with it, and `LaneConsolePane`'s lane-switch effect
wiped a half-typed prompt. It flipped on every page load (lanes arrive,
`refreshLanes` selects `lanes[0]`), on a lane being removed, and on any
refetch that re-picked the selection.
`lane-detail` is now always rendered and holds the only `ConsoleArea`;
the header and info block are the conditional parts. Same rule the
RunConsole already followed one level down — collapse with CSS, never by
unmounting — now enforced above it too.
Second half: every poller fed `setState` a brand-new object graph each
tick, re-rendering the lane strip, the card and the console area several
times a minute on a completely idle dashboard. `keepIfSame` keeps the
previous reference when the payload is value-identical, applied to the
5 s run/session poll, the lane list and counts, the `lane_update` WS
branch, and LaneCard's git/runtime/locks pollers.
Verified: npm run test:client (44 files / 454 tests), tsc --noEmit
clean, check-headers.sh clean. The Run screen snapshot was regenerated —
the diff is the added `<section>` wrapper and one indent level, no
content change.
