Closes the silent no-op when _allTasks is null on first launch (the
onboarding bulkCreateTasks path). The function now upserts: builds an
empty kanban shell with the standard column names if needed and places
the task in its target column. Unknown column names append a new
column at the end so the task is always reachable.
Also drops the second branch that conditionally wrote to
_tasksByResidence — that cache is being deleted in Phase 3 and
updateTask should not maintain it any more.
The Phase 1 unit tests now pass; the Phase 2 force-refresh in the
next commit replaces the placeholder column metadata (display names,
colors, icons) with authoritative server values.
Trey t
5d0c3597fa