WARDEN-WP-0026 finish Strand A (T04/T05/T07)

Promote railiance-backup-offsite-lane to active/resolvable after
capabilities-safe re-verify. Add catalog risk=high, agent read-boundary
(exit 7 + OpenBao policy companion), EXPOSED taint via warden taint, and
close WP-0026.

tests/test_proxy.py

@@ -383,3 +383,39 @@ def test_access_fingerprint_masks_and_bypasses_stdout_guard(monkeypatch, tmp_pat
     assert r.exit_code == 0
     assert "top-secret-token-value" not in r.output   # value never shown
     assert "hidden" in r.output and "sha256:" in r.output
+
+
+def test_access_agent_high_risk_raw_stream_refused(tmp_path, monkeypatch):
+    """WP-0026 T04: WARDEN_AGENT_ID + risk=high refuses raw value stream (exit 7)."""
+    _proxy_env(monkeypatch, tmp_path)
+    monkeypatch.setenv("VAULT_TOKEN", "caller-token")
+    monkeypatch.setenv("WARDEN_AGENT_ID", "grok")
+    # Prefer high-risk lane; use --unsafe-stdout so T02 would allow if T04 failed.
+    r = runner.invoke(
+        app,
+        [
+            "access", "railiance-backup-offsite-lane",
+            "--fetch", "--no-policy", "--unsafe-stdout",
+        ],
+    )
+    assert r.exit_code == 7, r.output
+    assert "agent read-boundary" in r.output.lower() or "risk=high" in r.output.lower()
+
+
+def test_access_agent_high_risk_fingerprint_allowed(tmp_path, monkeypatch):
+    """Agents may use --fingerprint on high-risk lanes (no raw value)."""
+    _proxy_env(monkeypatch, tmp_path)
+    monkeypatch.setenv("VAULT_TOKEN", "caller-token")
+    monkeypatch.setenv("WARDEN_AGENT_ID", "grok")
+
+    class _Fake:
+        returncode = 0
+        stdout = "should-not-appear"
+
+    monkeypatch.setattr("warden.proxy.subprocess.run", lambda *a, **k: _Fake())
+    r = runner.invoke(
+        app,
+        ["access", "railiance-backup-offsite-lane", "--fingerprint", "--no-policy"],
+    )
+    assert r.exit_code == 0, r.output
+    assert "should-not-appear" not in r.output