The hub hands its live terminal to detail/project_detail on open (already
flash-free going in), but both sub-views unconditionally tore the terminal
down on exit; the hub's next loop iteration then always called tui::setup()
again, producing a real LeaveAlternateScreen -> (plain terminal visible for
one frame) -> EnterAlternateScreen blink on every trip back.
- detail::run / project_detail::run now return the live terminal on a clean
exit instead of tearing it down (only torn down if the inner loop itself
errors); hub::tui_phase accepts an already-live terminal and skips its own
setup() when given one, threading it across loop iterations
- project_detail's own nested repo-detail call (Enter on its Repos tab) had
the same issue one level down, fixed the same way via Option<Tty> so the
terminal can be taken out for the nested call and put back
- verified via raw pty byte counts: two full hub<->detail round trips now
show zero EnterAlternateScreen/LeaveAlternateScreen pairs in between,
vs. one pair per trip before
dualfroz