Return the most recent records of a dataset (newest first).

Public access limited to 500 rows, admin gets up to 1000. limit is a positive bounded input (W-FS-02: a negative value reached SQLite as LIMIT -1, which means unlimited, and defeated the public sample cap). Pass sample=random for a random QA sample instead of newest-first — the default MUST stay newest-first: this endpoint backs /data/all-data, which press and analysts reach from the weekly digest expecting to find the current week's notices (NYT complaint, 2026-07-15).