Record each attempt before sending so a request lost to a deadline still
waits out MeshMapper's limit, and stop holding the directory lock across
HTTP. Groups now qualify only through heard or configured IATAs, and one
missing country list only skips pruning.
Region-filtered /scopes and /stats/scopes now list manual scopes configured
for the region and imported scopes whose MeshMapper catalogue includes the
IATA, instead of inferring membership from observed traffic. Filtered
/scopes returns string[] like the unfiltered call.
Manual scopes now require a region in config.
A transient failure pushed the next attempt out by the full refresh interval. Failures now retry in five minutes, with a server Retry-After still honoured as a ceiling.