calendar: use the host's calendar field names so all-day and multi-day events render in the Calendar view

[michielbdejong]

From Michiel's calendar user-testing session.

The calendar drive app (#101/#145) writes the shortnames day and all-day, and has no end-day property. The host's Calendar view (atomic-server CalendarView.tsx) reads the shared contract in @tomic/lib calendarFields (browser/lib/src/calendar-date.ts):

• atomic-calendar-day: a civil date YYYY-MM-DD;
• atomic-calendar-all-day: a boolean;
• atomic-calendar-end-day: the inclusive last day;
• atomic-calendar-notes.

Each can also carry an lt-google-calendar-property- prefix. Imported ranges are opt-in: only rows whose date column matches atomic-calendar-day get all-day and multi-day handling. So the app's all-day and multi-day events render as single-day events in the host view, which is also where the app's Month button hands off to.

Decision: fix the app, not the host. calendarFields is the shared contract other importers follow.

Fix:

• rename the app's day → atomic-calendar-day and all-day → atomic-calendar-all-day;
• add atomic-calendar-end-day (the inclusive last day, derived from Google's exclusive end);
• write the event description to atomic-calendar-notes if the app imports one;
• release as app 0.1.1, since published modules are immutable;
• extend the e2e to open the host Calendar view and assert that a multi-day all-day event spans its days.

Existing installs are experimental test installs only, so there's no migration beyond a re-import.

[michielbdejong]

Correction to the description: the host treats atomic-calendar-end-day as exclusive, not the inclusive last day. The Calendar view shows an all-day row on days ≥ day and < end-day, and adding an item in that view sets end-day to the day after. So the fix writes Google's own exclusive end date for all-day events. For timed events that cross midnight it writes the date the event ends, and for single-day timed events no end-day. The fix is ready (calendar app 0.1.1, with an e2e that opens the host Calendar view and checks that a 3-day event spans exactly the 10th–12th) and waits for #171 to land first.