`queryCalendarEvents` forwarded the `MutableStateFlow` it accumulates
the provider results in, so the initial empty value was the first thing
collectors saw - before any provider had reported. Callers in the
launcher take that first result (`CalendarPartProvider` uses `.first()`)
and cannot tell it apart from "no events", so the agenda stayed empty
and its part never showed up.
`CalendarRepository.findMany`'s 500 ms debounce used to hide this: the
placeholder was superseded by the real list within the debounce window,
which is exactly why the agenda only ever appeared half a second late.
Keep the accumulator null until the first provider reports, and let
`findMany` - a one-shot query for the clock and calendar widgets - wait
for all providers (`awaitAllProviders`) so it never hands out a partial
list. The search path keeps streaming results as providers report, now
without an empty flash.
Jonas Haugesen
4836618609