Stage 5 dc0 F-A/BUNDLEFIX-054: correct bundle.yaml HA-chain header + session changelog ...

- bundle.yaml:23 HA-chain header was stale after BUNDLEFIX-053 (vault-hacluster),
  the D-020 amendment (vault metal-only VIP) and R11 (designate VIP). Corrected FROM
  the measured merged dc0 deploy input: 12 -> 13 hacluster subordinates/:ha relations;
  ALL 13 carry a VIP (12 the full provider+metal-admin+metal-internal triple, vault a
  METAL-ONLY pair per D-020); retired the stale "designate has no HAProxy VIP" note
  (designate gained triple VIP .62 under R11); clarified rabbitmq is the 14th HA app but
  native-clustered (not in the 13). COMMENT-ONLY -- no deploy semantics change.
- Session changelog docs/changelog-20260806-stage5-dc0-f4-postwave.md (GA-R2):
  F4 (14/14 measurement-backed + vault ha_enabled), F8 (ceph-radosgw resolved),
  F9 (staging drift measured, re-stage gated), F-A, and the Task #1 finding that
  dc-ha-scaleup.yaml is now redundant with bundle.yaml (recommend retiring; operator
  ruling owed since R6/D-121 reference it -- logged, not executed).

Gauntlet ALL GREEN (99); repo-lint 0 fail (1 pre-existing legacy L1 warn).
Revert: git revert this commit (restores the prior 6-line header; changelog is additive).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Fg98z7QyzwYUs8fsWCn728