Swap github.com/phuslu/iploc for the shared net/geoip package,
matching the pattern established by check-ip. AllowedCountries now
reads CountryISO off fm.Geo.Value().Lookup(ipStr) instead of
iploc.IPCountry, so the same GeoLite2 databases serve both callers
and refresh on the same cadence.
New field: Geo *dataset.View[geoip.Databases]. Required when
AllowedCountries is set; if Value() is nil (pre-load), the check is
skipped (unknown = allow), matching the prior iploc behavior on
unknown IPs.
- Drop CohortSource interface — it had exactly one implementation.
Blacklist is now *dataset.View[ipcohort.Cohort] directly, matching
check-ip's usage. One concrete type, no premature abstraction.
- SMTP 15s → 5s, MX 3s → 2s. A relay or resolver that isn't
responding inside those bounds isn't going to deliver the mail;
faster failure is better than holding the request goroutine.
check-ip and geoip no longer use it; formmailer now takes
*atomic.Pointer[ipcohort.Cohort] for Blacklist so callers own the
refresh + swap lifecycle directly. gitshallow doc comments that
referenced dataset.Syncer are trimmed.
The concepts the package tried to share (atomic-swap, group sync,
ticker-driven refresh) may come back under sync/dataset once we have
more than one in-tree caller that wants them.
- Each package gets its own go.mod: net/{dataset,httpcache,gitshallow,ipcohort,geoip,formmailer}
- go.work with replace directives for cross-module workspace resolution
- dataset.Syncer/NopSyncer moved here from httpcache; callers duck-type it
- dataset.View[T] returned by Add to prevent Init/Sync/Run misuse on group members
- cmd/check-ip moved from net/ipcohort/cmd/check-ip to top-level cmd/check-ip
- Add net/ipcohort/cmd/ipcohort-contains for standalone cohort membership testing
