docs(WARDEN-WP-0014): T5 — assist-layer docs, security model, INTENT/SCOPE

- wiki/OperatorAccessAssist.md: warden access contract, conduit-vs-broker
  boundary, the three guardrails + catalog secret guard, lane semantics.
- AccessRouting.md: issue/route/assist roles; reconciled the anti-pattern
  table so the transparent conduit no longer contradicts it.
- credential-routing.md rule: added warden access + "standing broker
  forbidden, transparent --fetch sanctioned" anti-pattern.
- INTENT.md: pointer→assist charter extension. SCOPE.md: implemented
  list + Getting Oriented + maturity A4→A5 (Availability).
- history decision record for the proxy-mode choice and guardrails.

WP-0014 finished (T1–T5). 172 passed, lint clean.

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

INTENT.md

@@ -46,10 +46,14 @@ owns one lane and points at the rest:
 
 1. **Know** the NetKingdom security model — identity, authorization, secrets,
    SSH access, tunnels, bootstrap custody, and tenant/platform boundaries.
-2. **Route** workers to the correct subsystem for each credential type instead
-   of becoming a universal secret vending machine — through the wiki and a
-   machine-readable routing catalog that *points at* the owner's docs rather than
-   restating them.
+2. **Route, and assist.** Point workers to the correct subsystem for each credential
+   type instead of becoming a universal secret vending machine — through the wiki and
+   a machine-readable routing catalog that *points at* the owner's docs rather than
+   restating them. Beyond pointing, **assist**: the `warden access` front door renders
+   the exact auth method, path, and command for any need and — for `exec_capable`
+   lanes — proxies the fetch *as the caller* (a transparent, policy-gated, audited
+   conduit that holds, caches, and logs **nothing**). This is the assist layer, not a
+   broker: custody stays in OpenBao, authorization in flex-auth.
 3. **Align** runbooks, wiki, inventory patterns, and scorecard checks with
    NetKingdom canon as the platform evolves (OpenBao-first, flex-auth policy,
    key-cape IAM Profile, railiance deployment layers).
@@ -169,9 +173,10 @@ ops-warden (issue SSH; route the rest)
         +-- Tunnel only? --------------------> ops-bridge + cert_command
 ```
 
-Today the steward role is primarily documentation, runbooks, and the implemented
-SSH CLI. The machine-readable routing catalog and `warden route` lookup, plus
-policy-gated issuance, are intentional follow-ups, not current promises.
+The steward role spans documentation, runbooks, the SSH CLI, the machine-readable
+routing catalog with `warden route` lookup, policy-gated issuance, and — since
+WARDEN-WP-0014 — the `warden access` assist layer that advises and (for `exec_capable`
+lanes) proxies non-SSH fetches as the caller without holding the value.
 
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