Documents the cold-restore spawn fan-out point (renderer connect layer),
the daemon-init barrier's effect on an immediate first terminal, the
uncached in-daemon Windows shell resolution, and residual tab-switch
costs, so the follow-up work starts from measured locations.
CDP-driven harness measuring tab creation, tab switching, and workspace
switching against the real dev app with renderer-clock phase timings
(store -> PTY bind -> first output -> paint settle), longtask counts, and
WebGL context diagnostics. Reuses the windows-apphang-repro session
helpers; records ORCA_PTY_SPAWN_TIMING attribution when enabled.
Jinwoo Hong