Preserve Warden config in attended child

Assistant: codex
Assistant-Model: gpt-5.6-sol
Assistant-Session: 01a058f3-8ba0-7692-a042-9a870fc3d663

src/warden/proxy.py

@@ -403,6 +403,10 @@ def proxy_attended_login_exec(
     root, session, root_created = _prepare_attended_login_home()
     helper = session / _TOKEN_HELPER_NAME
     env = _caller_env()
+    if not env.get("WARDEN_CONFIG"):
+        caller_config = Path.home() / ".config" / "warden" / "warden.yaml"
+        if caller_config.is_file():
+            env["WARDEN_CONFIG"] = str(caller_config)
     env["HOME"] = str(session)
     env.pop("BAO_TOKEN", None)
     env.pop("VAULT_TOKEN", None)

tests/test_proxy.py

@@ -427,6 +427,34 @@ def test_attended_login_contained_success_output_never_escapes(monkeypatch, tmp_
     assert not (tmp_path / ".warden-attended-login").exists()
 
 
+def test_attended_login_preserves_caller_warden_config_for_reviewed_child(
+    monkeypatch, tmp_path
+):
+    monkeypatch.setattr(Path, "home", lambda: tmp_path)
+    monkeypatch.delenv("WARDEN_CONFIG", raising=False)
+    caller_config = tmp_path / ".config" / "warden" / "warden.yaml"
+    caller_config.parent.mkdir(parents=True)
+    caller_config.write_text("backend: local\n")
+    seen_config = None
+
+    def fake_run(argv, **kw):
+        nonlocal seen_config
+        helper = Path(kw["env"]["HOME"]) / ".vault-token"
+        if argv[:2] == ["bao", "login"]:
+            helper.write_text("non-production-test-double")
+            helper.chmod(0o600)
+        if argv == ["reviewed-child"]:
+            seen_config = kw["env"].get("WARDEN_CONFIG")
+        return subprocess.CompletedProcess(argv, 0, stdout=b"", stderr=b"")
+
+    monkeypatch.setattr("warden.proxy.subprocess.run", fake_run)
+    assert proxy_attended_login_exec(
+        ResolvedFetch(argv=["bao", "login", "-no-print"]),
+        child_argv=["reviewed-child"],
+    ) == 0
+    assert seen_config == str(caller_config)
+
+
 def test_real_catalog_login_entry_is_login_lane():
     from warden.routing import load_catalog
     e = load_catalog(_repo_catalog()).get("key-cape-oidc-login")