Day and night and nothing but: MISSION DEFAULT leaves the toggles b18df38

The two environment toggles on the main menu used to have a third stop — MISSION DEFAULT — which mostly asked the pilot to guess what it meant. No more:

1. DAY ↔ NIGHT. T is now a straight two-way switch; the row always reads exactly what you'll get: NOW: DAY or NOW: NIGHT.
2. CLEAR → CLOUDS → RAIN → STORM. R cycles the four weathers and stops nowhere else.
3. Authored sorties keep their briefing. Untouched, a mission still flies at its authored time — the Bear still comes at night. The moment you flip the switch, your choice becomes an explicit override. The plane-select screen shows the same two-state readout, and saves with an old pick migrate cleanly.