feat: complete local layer model v0.7 conformance work

Assistant: codex
Assistant-Model: gpt-6-astra
Assistant-Session: 01a06eaf-3425-7f92-a0c2-bb4aa4faebe4

tests/test_access.py

@@ -6,7 +6,7 @@ from pathlib import Path
 
 from typer.testing import CliRunner
 
-from warden.access import expand_handoff, policy_gate_status
+from warden.access import agent_read_boundary_identity, expand_handoff, policy_gate_status
 from warden.cli import app
 from warden.routing.models import RouteEntry
 
@@ -64,6 +64,33 @@ def test_policy_gate_status_no_config(monkeypatch, tmp_path):
     assert "advisory" in policy_gate_status()
 
 
+def test_issued_coding_agent_subject_drives_read_boundary_without_legacy_marker():
+    env = {"WARDEN_POLICY_SUBJECT": "service:codex:railiance-platform"}
+    assert agent_read_boundary_identity(env) == "service:codex:railiance-platform"
+
+
+def test_legacy_agent_marker_remains_fail_toward_safety_fallback():
+    env = {"WARDEN_AGENT_ID": "grok"}
+    assert agent_read_boundary_identity(env) == "grok"
+
+
+def test_non_agent_policy_subject_does_not_manufacture_agent_identity():
+    env = {"WARDEN_POLICY_SUBJECT": "iam:bernd"}
+    assert agent_read_boundary_identity(env) is None
+
+
+def test_explicit_empty_environment_does_not_inherit_process_identity(monkeypatch):
+    monkeypatch.setenv("WARDEN_AGENT_ID", "codex")
+    monkeypatch.setenv("WARDEN_POLICY_SUBJECT", "service:codex:railiance-platform")
+    assert agent_read_boundary_identity({}) is None
+    assert agent_read_boundary_identity() == "service:codex:railiance-platform"
+
+
+def test_operator_subject_does_not_override_legacy_agent_marker():
+    env = {"WARDEN_POLICY_SUBJECT": "iam:bernd", "WARDEN_AGENT_ID": "codex"}
+    assert agent_read_boundary_identity(env) == "codex"
+
+
 # --- CLI -------------------------------------------------------------------
 
 def test_access_advisory_output(monkeypatch):