atmo.rsvp

fix(search): give the band a Meilisearch path, and index the instant master

Groundwork the Happening Now band needs before it can run on the backend the list beneath it runs on. A band ranked by D1 sitting above a list ranked by Meilisearch can disagree with itself about which events are live, and does. Adds the ongoing query to the search backend and registers its two cursor names in the pagination envelope, so a band page resumes and deep-links like any other list. Normalises the two fields the index range-filters and sorts on. Meilisearch has no date type, so every bound is a string comparison, which is only chronological while every value is written the same way — and RFC 3339 does not require that. An .ics from Denver yields 2026-08-10T09:00:00-06:00, which collates by its wall-clock digits rather than by the instant it names, so it filters as if it were later than a UTC value it actually precedes. Sub-second precision is the same hazard in miniature: a stored 12:00:00Z compares greater than 12:00:00.500Z because 'Z' sorts above '.'. Storing the instant settles both. Unparseable input still passes through as written; dropping the field would silently remove the event from every bounded query.