Render schedules in a human-readable format

[dfalling]

Summary

The element detail screen printed schedules as raw ISO fragments in a machine-ish order — 2026-03-14 – 2026-03-16 · 09:15:00–17:00:00. That reads as data, not as a plan. Times now lead and the day they fall on follows, with everything redundant dropped.

Case	Before	After
All-day, one day	2026-03-14	Mar 14
All-day range	2026-03-14 – 2026-03-16	Mar 14 to Mar 16
Timed, one day	2026-03-14 · 09:00:00–17:30:00	9 AM to 5:30 PM, Mar 14
Timed range	2026-03-14 – 2026-03-16 · 09:15:00–17:00:00	9:15 AM, Mar 14 to 5 PM, Mar 16
Start time only	2026-03-14 · 12:00:00	12 PM, Mar 14
End time only	2026-03-14 · 17:00:00	Until 5 PM, Mar 14

Details:

• The year is omitted for the current year, and shown on both ends when either date falls outside it — so a New Year's range reads Dec 30, 2026 to Jan 2, 2027 rather than looking like it starts in 2027.
• Same-day timed schedules mention the date once instead of on both sides.
• Whole hours drop :00 — 5 PM, not 5:00 PM.
• allDay: true suppresses any times still stored on the record from an earlier edit.
• Dates are split by hand rather than parsed through Date, which would reinterpret the element's own timezone as the device's and slide the day.

Formatting moved out of ElementDetailScreen into src/map/formatSchedule.ts so it could be unit tested; times render 12-hour AM/PM with no locale awareness, matching the rest of the app.