Time zone resolver

Turns a wall-clock birth time and a pair of coordinates into an unambiguous instant. Every other endpoint here wants either a timezone-aware timestamp or a numeric UTC offset, and getting that wrong is the commonest cause of a chart that is quietly an hour or a day out, so this is usually the first call you make. Send `date`, `time`, `latitude` and `longitude`. The coordinates are resolved to an IANA time zone, the naive date and time are read in that zone, and you get back `input_datetime`, the resolved `timezone` name, `localized_datetime` with its offset attached, and `utc_datetime`. Feed the localised value straight into `date_time` elsewhere. One caveat: the request field is spelt `use_LMT` but the view reads a differently-spelt name, so local mean time is never actually applied and the IANA zone is always used — `use_lmt` in the response is always false. For births before standard time was adopted locally, work out the local mean time offset yourself (four minutes per degree of longitude) rather than relying on this flag.