Follows an upstream/vendor research pass answering "can Octavia run full
IPv6" -- yes; nothing inside Octavia requires IPv4. charm-octavia creates
the lb-mgmt subnet with ip_version: 6 and has no IPv4 code path at all; the
health manager is v6-capable both directions; the amphora agent binds '::'
and verifies certs by amphora UUID, not IP; and Nova metadata is not a
dependency (config_drive=True). Surviving v4 pressure is soft or external.

R8a BUILT. phase-05-octavia-verify.sh now compares o-hm0's MTU against
lb-mgmt-net's (resolved BY TAG, never by name), fails in either direction,
and REFUSES when a value cannot be read. This closes the LP#2018998
obligation, live on our exact pin after its 2025-12-31 recurrence.

THE DECISION RECORD HAD CLAIMED THIS SHIPPED. design-decisions.md carried a
present-tense "Delivery: the assertion ships in ..." written on the day of
the ruling, while the file held zero MTU references and its last commit
predated the ruling by a month. Corrected in place. Sharper than the usual
ruled-but-not-built class: the decision doc was the false witness.

TWO OWNED ERRORS:
- I concluded "no octavia harness exists" from a NAME grep. The script's
  harness has always been tests/phase-05. Duplicate deleted, R8a cases
  folded into the real one.
- My first MTU draft ABORTED the script: a $( ) under set -euo pipefail with
  inherit_errexit exits the run rather than reaching the refusal branch. The
  pre-existing harness I had just declared nonexistent caught it. Same class
  as commit 1's IFS word-splitting trap; both now locked by cases.

Two live surfaces still contradicted R8 -- dc-dc-phase4 and the workflow doc
both called lb-mgmt IPv6 "a real, open risk" and recommended keeping it
v4-only, citing the two refuted bugs. A reader would have re-litigated a
closed ruling in the wrong direction. Both superseded in place.

R7 executed: phase-01 Step 1.0-GEN gains a $DC selector; the baked
/CN=VR0 DC0 CA subjects derive from it, and the VIP gate derives this DC's
provider prefix from the same overlay it read the VIP from -- R7's explicit
"read the MERGED input" caveat. dc1's 10.12.64.57 used to hard-ABORT, so no
dc1 artifact could be produced. Verified both DCs, negative control still
aborts.

Logged not built: the controller cert's CN/DNS SANs still carry dc0.vr0
(outside R7's ruled scope, inert while os-public-hostname is unset), and it
gains no IPv6 IP SAN though the VIP is dual-family -- a gap, not a break,
and adding v6 SANs needs its own ruling.

tests/phase-05 14 cases (was 9); gauntlet ALL GREEN (85) on vcloud;
repo-lint 0 fail / 611 files.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HvCyrwvYTTcDYnRErfMsNf