v0.5.0

0.5.0 — Managed-setting and SKILL honesty

MINOR: the Claude managed-setting emitter and the generated SKILL note change, so an
adopter's next chock sync / chock plugin build rewrites those artifacts. No credited
enforcement surface changes — both are non-credited/advisory outputs being brought into
line with what they can actually deliver (do-not-claim, applied to the emitter itself).

• protect-main-branch managed-setting is now empty. It previously emitted a
  branch-blind command-text deny (commit.*\b(main|master)\b) that missed a plain
  git commit on main and false-positived on "main" in a message. A static managed
  setting cannot resolve branch state, so the honest managed-setting for branch
  protection carries no deny — enforcement lives in its git-hook and ci-gate surfaces,
  which do read the branch.
• scan-secrets managed-setting aligned to the gate. Added jks|keystore to the
  credential-file pattern and more high-confidence credential prefixes (xoxb, sk/rk_live,
  sk-ant, AIza, npm_) so the in-session echo is less of a silent subset of the git-hook.
  Kept lookahead-free for cross-client regex-engine safety; the git-hook remains
  authoritative.
• SKILL advisory note is conditional on artifact. A rule (advise-tier) policy no
  longer claims it "becomes a git hook that exits non-zero" when compiled — it ships rule
  text and stays advisory. Only hook policies carry that line; guard-script policies
  still get the enforced note in the per-client plugin formats.