Forward AAAA — re-attach instance records to the DNS view

[bcavnvidia]

Summary

The instance DNS-records view was orphaned from the combined DNS view by an earlier migration, so instance A and AAAA records are unreachable. Re-attach it. (The IPv6 hostname-label normalisation this once also covered has already shipped separately.)

Dependencies

• Overlay/01 — interface contract: addresses, dual-populate #2394 — the instance-inclusive address source.
• Overlay/12 — small type fixes (FQDN, Redfish bracket, capability guard) #2406 — well-formed IPv6 FQDNs (soft).

Additional Notes

• Stage: DNS-serving tail (deferred)
• Plan: IPV6_OVERLAY_PLAN/AUDIT_AND_TESTS_PLAN (sections 9.1 / 10.5)

[chet]

Heads-up: this overlaps the #2630 reverse-DNS work but points the opposite way. #2769/#2749 removed the dns_records_instance view and nico_inet_to_dns_hostname rather than re-attaching them -- the finding was that they were an orphaned, redundant SQL duplicate of the host-naming strategy (forward A/AAAA come from machine_interfaces.hostname via the shortname/adm views, which already set the record type by address family).

So the "re-attach it" premise needs a decision before this is actioned: if instance forward A/AAAA are already served through the machine-interface path, this is resolved-differently; if instances' network_config addresses need a path the shortname view doesn't cover, it's a real gap #2749 didn't close. Flagging rather than resolving.