… lands on the bifurcation

- Since the op runs in DeepOpService and survives backgrounding (ADFA-4957/4960), leaving no longer
  interrupts it. Back while running now shows a soft, mode-specific hint and returns to the
  bifurcation instead of hard-blocking: 'Backup/Restore is running — you can leave; it keeps going and
  will be ready when you come back.' (matches the module-index leave-hint). Drops the old
  'can't be interrupted' string (k2go_br_busy_wait, now unused).
- popToIntro: Finish (and cancels) always land on the bifurcation. In the deep-link case (reopened via
  the notification, no bifurcation underneath) it now shows the bifurcation — which runs the
  return-to-Home countdown — instead of jumping straight Home.

…directing (like the index)

The return-to-Home countdown was a blind 3s -> Home, which could drop the user on a Home still
starting (the state we hardened yesterday). Now it mirrors SetupProgressActivity: boot the environment
via serverController.startEnvironment() (unconditional, never the toggle) and poll RestReadiness.apiReady()
every 2s off the main thread until the REST core answers, THEN redirect to an already-live Home. Cancel
keeps the user on the bifurcation; a 45s timeout still goes Home so they're never trapped (Home's boot
gate then owns the rest).

…eric template loop)

Add the dedicated working loops (open box + streaming dots + glow; backup = phone->box, restore =
box->phone) and select them by mode in BackupJobFragment instead of the shared k2go_working_loop. Per
the design spec these replace the cloud with a box and still composite the K2Go logo via the app, so
the existing logo scaffold (right ~0.82W/0.53H) is unchanged. Also resolves the 'little cloud' note.

setTextAppearance() was called after setTextColor() on the countdown message, so Material3's default
(light) color overrode the intended teal, leaving it near-invisible on the pale info background (Cancel
was fine — it has no appearance). Set the color after the appearance.