feat(mvp): working secrets-engine CLI for the whynot-design npm publish lane

Implements SECRETS-WP-0002 end to end as a uv-managed Python package:

- catalog: non-secret lane registry + strict validator (build/test/prod)
- stage roles + OpenBao ACL policies; guards refuse wildcards, sys/, identity/,
  admin names, and cross-stage paths before any backend call
- plan/apply: dry-run-first, idempotent policy + approle apply, decision-gated
- decisions: State Hub lookup with local-fixture fallback; non-secret evidence
  to JSONL + hub progress, scrubbed of any value
- provision/verify: mode-0600 file import + generated test values; positive/
  negative checks that never print the value
- exec delivery: `exec --catalog ... -- npm publish` injects the token via a
  temp .npmrc for the child only, cleaned up on exit/failure/interrupt
- ops-warden routing contract + hardening backlog docs
- 34 tests incl. live OpenBao integration; scripts/demo-e2e.sh runs the full
  chain against a throwaway bao dev server

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/cli.md

@@ -0,0 +1,78 @@
+# secrets-engine CLI
+
+## Install
+
+```bash
+uv venv && uv pip install -e ".[dev]"
+source .venv/bin/activate
+secrets-engine --version
+```
+
+## Environment
+
+| Var | Default | Purpose |
+| --- | --- | --- |
+| `BAO_ADDR` | `http://127.0.0.1:8200` | OpenBao address |
+| `BAO_TOKEN` | _(unset)_ | OpenBao token (or use `--bootstrap-token-file`) |
+| `SECRETS_ENGINE_HUB_URL` | `http://127.0.0.1:8000` | State Hub for decisions + evidence (empty to disable) |
+| `SECRETS_ENGINE_CATALOG` | `./catalog` | catalog directory |
+| `SECRETS_ENGINE_EVIDENCE` | `./.evidence` | local non-secret evidence log |
+
+## Commands
+
+```text
+secrets-engine catalog list
+secrets-engine catalog show <catalog-id>
+secrets-engine decision inspect <decision-or-ccr-id>
+secrets-engine plan  <ref> --stage <build|test|prod>
+secrets-engine apply <ref> --stage <stage> [--dry-run] [--bootstrap-token-file F]
+secrets-engine provision <catalog-id> --stage <stage> --field NAME (--from-file F | --generate)
+secrets-engine verify <catalog-id> --field NAME [--positive] [--negative]
+secrets-engine exec --catalog <catalog-id> [--field NAME] [--mode auto|npm-config|exec-env] -- CMD...
+secrets-engine route <catalog-id> [--json]
+secrets-engine revoke <catalog-id> [--dry-run]
+```
+
+`<ref>` is a catalog id or a decision/CCR ref (matched against
+`approval.decision_ref`). `plan` and `apply --dry-run` never mutate OpenBao.
+
+## Exit codes
+
+| Code | Meaning |
+| --- | --- |
+| 0 | success |
+| 2 | catalog error (missing/invalid lane) |
+| 3 | decision error (unapproved / superseded / missing) |
+| 4 | policy guard error (out-of-stage / wildcard / broad admin) |
+| 5 | backend error (OpenBao unreachable / failed) |
+| 6 | provisioning error (bad file mode / inside repo / missing field) |
+| 7 | verification failed |
+| 8 | delivery error |
+
+## End-to-end demo
+
+```bash
+SECRETS_ENGINE_HUB_URL="" bash scripts/demo-e2e.sh
+```
+
+Boots a throwaway in-memory OpenBao dev server and runs the whole pilot chain:
+plan → apply → provision → verify(+/-) → exec (npm-config injection) → route →
+revoke. Nothing is persisted; the token is a throwaway local string.
+
+## Pilot: whynot-design npm publish
+
+```bash
+# 1. inspect the approved decision
+secrets-engine decision inspect whynot-design-npm-publish
+# 2. preview the OpenBao changes (no mutation)
+secrets-engine plan whynot-design-npm-publish --stage prod
+# 3. apply policy + approle
+secrets-engine apply whynot-design-npm-publish --stage prod
+# 4. provision the token from a mode-0600 file OUTSIDE the repo
+secrets-engine provision whynot-design-npm-publish --stage prod \
+  --field npm_token --from-file ~/.secrets-engine/whynot.token
+# 5. prove access without printing the value
+secrets-engine verify whynot-design-npm-publish --field npm_token --positive --negative
+# 6. publish with the token injected into the child only
+secrets-engine exec --catalog whynot-design-npm-publish -- npm publish
+```