v1.0.408

Let calendar events have an optional time

Tasks and events can now carry a start time and an optional end time. Untick
"At a set time" and an event is all-day again, as before. Birthdays stay
all-day.

A time is a wall-clock label in the household timezone ("17:00" is 5 PM),
never converted, so a recurring 5 PM stays 5 PM across a DST change. It only
affects display and ordering: overdue is still decided by date.

• API: time/endTime on create and update. An end time needs a start. On a
  multi-day event it falls on the last day; on a single day it must not
  precede the start, and an end equal to the start is dropped. time: null
  makes an event all-day and clears its end time, and both keys are deleted
  rather than stored as null.
• Projection: occurrences carry the times, and within a day all-day items
  sort before timed ones, in clock order.
• Calendar view: grid chips lead with a compact "5pm" when the chip has room
  (a container query keeps a task's title visible in a narrow cell), the
  agenda shows "2:00 PM – 3:00 PM", and the event dialog gets the inputs.
• Chat tools and Daily News (desk lines, Week Ahead box, email) carry the
  times too.
• Wall-clock helpers now live in server/wall-clock.ts, so the server-rendered
  Daily News and the frontend share one formatter. Timesheet's formatClock
  and isValidTime come from there.