Timestamps need an offset

The rules

These rules decide what a correct result is. Your answer is checked on this dataset and on hidden datasets that follow the same rules.

Input
  events(id, raw_ts) — text. id is unique.

Rules
  Accept raw_ts when it is YYYY-MM-DD, "T" or one space, HH:MM[:SS[.fraction up to 6 digits]], then an explicit
  offset (Z or ±HH:MM, at most ±14:00); hour 00–23, minute/second 00–59; the date must exist. Convert to UTC.
  2026-11-01T01:30:00-04:00 and 2026-11-01T01:30:00-05:00 are different instants.
  Quarantine with reason:
    missing_offset   a well-formed date and time with no offset (never assume a zone)
    bad_timestamp    anything else, including missing values

Outputs (row order does not matter)
  clean(id text, ts timestamptz [UTC])
  exceptions(id text, reason text)