- Cruise altitude 2.6 -> 2.0 (just above cloud ceiling y=1.5,
gives the 'just above the clouds' airliner feel)
- Expose __currentSunAlt (radians) from animate() so the
renderer can tell night from day without misreading
realDayProgress (which mixes pre-dawn + post-sunset hours)
- Replace (1 - uDayProgress) star gate by smoothstep over uSunAlt:
nightFactor = 1 when sun is well below horizon, 0 when above
- Widen sky band so stars are visible from the horizon upward
(cockpit-perspective frame is mostly below rd.y=0.3)
Richard Zink
5e66cdfa2b