feat(WARDEN-WP-0019): route secret-exec lanes to secrets-engine (route-primary, proxy fallback)

secrets-engine (SECRETS-WP-0003) shipped a native secret-exec front door
(`secrets-engine route/exec`, decision e6381a56) and asked ops-warden to route to it.
Bernd's call: route-primary, proxy-fallback — surface the secrets-engine exec as the
primary path for owned lanes, keep `warden access --exec` as a transparent fallback.

T1 — RouteEntry gains exec_owner/exec_command/pointer_command (+ has_native_exec),
screened for secret material like the other handoff fields. whynot-design-npm-publish
points its native exec at secrets-engine. `warden access` renders Primary (secrets-engine
exec) + Fallback (warden proxy); route/access JSON gain the fields and a native-exec-aware
next_action. Tests added; 217 pass, lint clean.

T2 — credential-routing.md adds secrets-engine as the secret-exec owner (route primary,
proxy fallback); SCOPE adds secrets-engine to Related Repos and records the npm lane as
production-exercised (@whynot/design@0.4.0); playbook leads with secrets-engine exec and
fixes the fallback one-liner (--field NPM_AUTH_TOKEN, --no-policy) per whynot-design.

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

workplans/WARDEN-WP-0019-route-to-secrets-engine.md

@@ -0,0 +1,86 @@
+---
+id: WARDEN-WP-0019
+type: workplan
+title: "Route secret-exec lanes to secrets-engine (route-primary, proxy fallback)"
+domain: infotech
+repo: ops-warden
+status: finished
+owner: claude
+topic_slug: custodian
+planning_priority: high
+planning_order: 19
+created: "2026-06-29"
+updated: "2026-06-29"
+---
+
+# WARDEN-WP-0019 — Route secret-exec lanes to secrets-engine
+
+**Trigger:** secrets-engine (SECRETS-WP-0003, msg 765a03f0) shipped a native secret-exec
+front door — `secrets-engine route <id> --json` and `secrets-engine exec --catalog <id> --
+<cmd>` with canonical decision ids — and asked ops-warden to **route to it**. This is the
+owner-native execution lane that ops-warden's `warden access --exec` proxy was filling as a
+stopgap (WP-0014). whynot-design already published `@whynot/design@0.4.0` through the proxy
+on this same lane, so both paths resolve today.
+
+**Decision (Bernd, 2026-06-29): route-primary, proxy-fallback.** For lanes secrets-engine
+owns, ops-warden surfaces `secrets-engine exec/route` as the **primary** path and keeps its
+own `warden access --exec` as a documented **transparent fallback**. ops-warden stays the
+discovery front door; secrets-engine is the exec owner. Boundary unchanged: ops-warden holds
+or stores no token on either path.
+
+**Out of scope:** ops-warden invoking `secrets-engine exec` itself (it routes/points, the
+caller runs it); changing the proxy's security model; the production policy-gate flip.
+
+---
+
+## Tasks
+
+### T1 — Catalog + CLI: surface the owner-native exec front door
+
+```task
+id: WARDEN-WP-0019-T01
+status: done
+priority: high
+```
+
+- [x] `RouteEntry` gains `exec_owner` / `exec_command` / `pointer_command` (pointers only,
+      screened by `_assert_no_secret_material`) and a `has_native_exec` property.
+- [x] `whynot-design-npm-publish` entry: `exec_owner: secrets-engine`,
+      `exec_command: secrets-engine exec --catalog whynot-design-npm-publish -- <cmd>`,
+      `pointer_command: secrets-engine route whynot-design-npm-publish --json`. Keep the
+      existing `fetch_command`/`exec_capable` (the proxy fallback).
+- [x] `warden access`: when `exec_owner` is set, render the secrets-engine exec as the
+      **primary** line and the `warden access --exec` proxy as the **fallback**; JSON gains
+      `exec_owner`/`exec_command`/`pointer_command`. `route find/show` JSON too.
+- [x] Tests in `tests/test_routing.py` / `tests/test_access.py`.
+
+### T2 — Agent rule, SCOPE, playbook
+
+```task
+id: WARDEN-WP-0019-T02
+status: done
+priority: medium
+```
+
+- [x] `.claude/rules/credential-routing.md`: add secrets-engine as the secret-exec owner;
+      for OpenBao-backed secret lanes the route is "secrets-engine `exec` (primary),
+      ops-warden `warden access --exec` (transparent fallback)".
+- [x] SCOPE: add secrets-engine to Related Repos + the routing model; note the
+      whynot-design lane is **production-exercised** (real 0.4.0 publish), not just resolvable.
+- [x] `wiki/playbooks/whynot-design-npm-publish.md`: lead with the secrets-engine exec
+      command; fix the fallback one-liner per whynot-design's field notes
+      (`--field NPM_AUTH_TOKEN`, and `--no-policy` while `policy.enabled=false`).
+
+---
+
+## Acceptance
+
+- `warden access whynot-design-npm-publish` shows the secrets-engine exec as primary and the
+  warden proxy as fallback; `--json` carries `exec_owner`/`exec_command`.
+- The credential-routing rule names secrets-engine as the secret-exec owner.
+- No secret material anywhere; ops-warden holds no token on either path.
+
+## See also
+
+- secrets-engine SECRETS-WP-0003, decision e6381a56, `docs/whynot-design-real-publish-closeout.md`
+- `WARDEN-WP-0014` (proxy), `WARDEN-WP-0017` (discoverability), `WARDEN-WP-0018` (lane activation)