Parse and expose SessionStatus from the official live feed, treating Started/Resumed as active and terminal or missing statuses as inactive archive candidates.
Keep /api/v1/live/state and SSE snapshot data reserved for active sessions while exposing memory-only last_snapshot, last_positions, and last_snapshot_at for the explicit Live tab archive view.
Mocks /api/v1/live/state with a race snapshot to exercise the tower,
flag banner, weather strip, battle detection, stint history, and
driver pinning; also covers the no-session empty state.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
