An itinerary, answered leg by leg

Fans out over the same engine `/v1/check` uses — one evaluation per (passport, destination node). It does not add a trip model.

**Three things it refuses to pretend.** A sub-national region (`CA-BC`, `US-OH`) is answered `unknown`, never coerced to its country. An airport not among the ports we hold is answered `unknown`, never guessed. And a connection is evaluated as an entry, because this body cannot express whether the traveller clears immigration — which over-requires rather than under-requires.

`meta.coverage` is `full`, `partial` or `out_of_coverage`. A trip touching none of our four markets says so explicitly: it is *not* an answer that nothing is required.