* perf(routes): batch cross-IATA and hash route search (#216)
One search fired a /routes/cross request per IATA pair (138k on 2026-10-08). Route search now takes an optional iatas list and runs a fixed number of index-backed queries. /info advertises built-in minimum client versions.
* chore: bump version to 2.0.4
GET /traces takes an optional cursorTag so tags sharing a millisecond survive
paging. Migrations run under an advisory lock and record each file in the
same implicit transaction, so a crash can't strand a fresh database.
Overview windowHours counts the hours it covers, hourly observer activity
fills unrolled hours from raw rows, and integration fixtures are UTC.