feat(WARDEN-WP-0017): make the access front door discoverable (not SSH-only)

WP-0014 made ops-warden the operator access front door (warden access --fetch/--exec
proxies an exec_capable secret as the caller), but every discovery surface still told
the pre-WP-0014 "SSH certs only, pointer not key" story — so agents like whynot-design
never found the proxy and concluded they had to message ops-warden for a token value.

Messaging/discoverability only; the conduit security model is unchanged (no custody,
no broker).

T1 — CLI: `warden route` table warden column is now three-valued (issue/assist/route);
route + access JSON gain warden_role + exec_capable and a proxy-aware next_action;
`warden access` closing line leads with "ops-warden can fetch this for you as the
caller" for exec_capable lanes (route-only lanes keep "owner vends").

T2 — .claude/rules/credential-routing.md reframed (lead + routing table role column);
SCOPE one-liner + a second capability block for the access front door.

T3 — registered the State Hub capability "Operator access front door (caller-identity
fetch proxy)" (the hub had no ops-warden security capability at all); messaged
whynot-design the corrected `warden access "npm auth token" --fetch/--exec` path.

210 tests pass, lint clean.

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

tests/test_access.py

@@ -72,7 +72,17 @@ def test_access_advisory_output(monkeypatch):
     assert r.exit_code == 0
     assert "railiance-platform" in r.stdout
     assert "platform/workloads/coulomb_social/" in r.stdout
-    assert "does not hold this secret" in r.stdout
+    # npm is an exec_capable lane → the front door leads with the proxy, not "owner vends".
+    assert "can fetch this for you" in r.stdout
+    assert "never holds" in r.stdout
+
+
+def test_access_route_only_lane_says_owner_vends(monkeypatch):
+    """A non-exec lane (host principal deploy) keeps the advise-only framing."""
+    monkeypatch.setenv("WARDEN_ROUTING_CATALOG", str(_repo_catalog()))
+    r = runner.invoke(app, ["access", "host principal deploy"])
+    assert r.exit_code == 0
+    assert "warden advises, the owner vends" in r.stdout
 
 
 def test_access_json_shape_is_secret_free(monkeypatch):