Add `POST /api/measurements/bulk-delete` and `POST /api/mood-entries/bulk-delete`,
mirroring the bulk-insert conventions (`withIdempotency`, per-user rate
limit, response envelope). Body is `{ ids: string[] }`, capped at 200.
Soft-delete only, ownership-scoped: a single `updateMany` pins `userId` +
`deletedAt: null` and sets `deletedAt` + bumps `syncVersion`, matching the
single-DELETE iOS tombstone contract. A forged or foreign id is a silent
no-op — the returned `deleted` count reflects owned rows only, never a 404
existence leak.
Side effects fan out efficiently: measurements collapse the deleted rows to
the unique `(type, day)` set before recomputing rollups (one recompute per
type-day, not per row) and invalidate the affected status-insight caches;
mood collapses to the unique day set for its rollup recompute. Both bust the
per-user read caches.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
