0 (idle) … 1 (complete). Subscribe to drive any renderer.
begin — jump to a visible head (8%).
advance one asymptotic step toward the 95% ceiling (call on an interval while loading).
complete — snap to 100% (consumer then resets after a fade).
back to idle (0%).
set an explicit value (clamped 0..1).
0 (idle) … 1 (complete). Subscribe to drive any renderer.