The cursor was the last row's last_seen in ms, so routes sharing that
millisecond (common within one upsert batch) never came back. GET /routes
takes an optional cursorId, backed by keyset indexes; cursor alone keeps
working as before.
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.
MrAlders0n