Identifiers consumed: BUNDLEFIX-010. Also records the operator's D-068
AMENDMENT (no new D number) and window addendum 15.

- bundle.yaml: vault channel 1.16/stable -> 1.8/stable, comment replaced
  with amendment rationale (1.16 = incompatible charm line for this
  reactive cloud). Gates: provider-bundle-check PASS, channel_assert PASS
  (29 pins), repo-lint 0 fail.
- docs/design-decisions.md: D-068 AMENDMENT (2026-07-05) verbatim from
  operator; 1.16 ruled out, off-EOL-1.8 remains OPEN; D-002 item-3
  supersession withdrawn. Evidence: docs/D-068-vault-1.8-vs-1.16-analysis.md.
- changelog addendum 15: G2 (octavia 542) + G3 (dashboards 750/122/168)
  complete; dashboard-VIP-HTTPS RCA = since-deploy build defect (haproxy
  L4-masked vhost-less backend), phase-03 3.3 check fails open; G3 stands,
  no revert; upstream bug + DOCFIX candidates queued post-window.
- session-ledger: jumphost fence updated; machine-derived reseeded
  (BUNDLEFIX next-free 011).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FCGjrRXtbPRu5qEThw3CDz