EPIC D at HEAD: five named capabilities, measured against tracked code

Issue #3309 names five CC capabilities to adopt. A 2026-08-16 triage recorded three of them as PRESENT and proposed a bookkeeping close. Re-probed against tracked files at origin/main, none of the three is in code. This PR adopts two of them, in this repo's project scope, and states plainly why the third is declined. It does not close the epic.

Probe at origin/main, and what this PR does

Effect of bin/worktree-config.sh --apply

The probe commands are plain git, run against origin/main rather than a working tree: git cat-file -e origin/main:.worktreeinclude and git show origin/main:bin/worktree-config.sh | grep -c baseRef. That distinction is the whole finding: .claude/settings.json is gitignored, so a probe that reads the local file, or reads reference prose, reports adopted for something no clone receives.