Introduce service.ErrProviderUnavailable, wrapped only around the
provider GetRecords call in ZoneRecords. handleZoneRecords and
handleTemplateFromZone now use errors.Is against it to tell a real
provider outage (502) apart from local resolution failures such as an
unknown domain (404), instead of collapsing every ZoneRecords error
into a blanket 502. Also fixes handleTemplateFromZone's GetDomain
error branch to return 404 "domain not found" instead of 500, for
consistency with handleSetDomainTemplate/handleDomainHistory.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BwxdSt4reTm7Dj1oxRvpP3
LoadDomain requires a template, so a zone without one could never be
viewed or snapshotted. Adds a template-free path: store.LoadZone /
service.ZoneRef / DomainService.ZoneRecords read a zone's live records
straight from the provider (no diff, no template). GET
/domains/{did}/records exposes read-only viewing; POST
/domains/{did}/template-from-zone snapshots only managed record types
(NS/SOA excluded) into a new template and auto-attaches it to the domain.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BwxdSt4reTm7Dj1oxRvpP3
vasyansk
