DOCFIX-139..141: repo-rename sweep (ipv4->dc-dc) + repo-lint L9 self-reference guard ...

New repo openstack-caracal-dc-dc still had stale operational references to the
source repo it was seeded from (openstack-caracal-ipv4), plus, after the
mechanical fix, hardcoded references to its own new name -- both break on any
future fork/rename. Fixes:

- DOCFIX-139/140: repaired 8 stale clone-path/URL references across the skill
  and 4 runbook RUN blocks; fixed a repo_lint.py Windows path-separator bug
  that silently turned a documented WARN into a FAIL (rel comparison used
  str() instead of as_posix()).
- DOCFIX-141: new repo-lint check L9 fails any script/RUN-block/skill file
  that hardcodes the current repo's own directory name. Narrowed the
  .claude exclusion in repo_lint.py to .claude/worktrees/ only (it was
  blanket-hiding checked-in .claude/skills and .claude/hooks from all
  lint checks). Established a $REPO session-variable convention
  (runbooks/README.md Conventions) and converted the 8 hardcoded paths to
  require it explicitly, fail loud if unset.

repo-lint: 0 fail / 1 documented legacy WARN. tests/repo-lint harness 34/34.
Full details + per-item revert instructions in the two changelogs.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QrcJx8TUar7pYAvpGJw57A