feat(agent): add full codex agent support (v4.2.0)

- Implement CodexAdapter in lib_py/agents/adapters/codex.py with safe flags and TUI readiness
- Extend create_session, resume_session, stop_session, and reconcile for codex CLI
- Support codex agent delegation and loop integration across all multi-agent skills
- Add unit, component, and contract test suites for codex integration
- Verify all 462 tests passing cleanly

tests/test_c1_tui_readiness.py

@@ -488,7 +488,7 @@ def test_c10_create_session_timeout_dead_pid_kills_session(mam_sandbox, mock_her
 def test_adapter_strong_weak_partition():
     """N-D: Verify strong_ready_tokens and weak_ready_tokens partition ready_tokens for all adapters."""
     from lib_py.agents.registry import get_adapter
-    for agent in ('claude', 'agy', 'hermes', 'grok', 'opencode'):
+    for agent in ('claude', 'agy', 'hermes', 'grok', 'opencode', 'codex'):
         adapter = get_adapter(agent)
         assert adapter is not None
         ready_set = set(t for t in adapter.ready_tokens.split('|') if t)
@@ -527,6 +527,8 @@ echo "7: $(check_sks 'claude')"
 echo "9: $(check_sks 'grok-02')"
 echo "10: $(check_sks 'creator-opencode-01')"
 echo "11: $(check_sks 'opencode')"
+echo "12: $(check_sks 'creator-codex-01')"
+echo "13: $(check_sks 'codex')"
 """
     res = _run_lib_helpers(script)
     assert res.returncode == 0, res.stderr + res.stdout
@@ -538,6 +540,8 @@ echo "11: $(check_sks 'opencode')"
     assert "9: RESOLVED_AGENT=grok" in res.stdout
     assert "10: RESOLVED_AGENT=opencode" in res.stdout
     assert "11: RESOLVED_AGENT=opencode" in res.stdout
+    assert "12: RESOLVED_AGENT=codex" in res.stdout
+    assert "13: RESOLVED_AGENT=codex" in res.stdout
 
 
 def test_f2_upsell_modal_defense_with_real_facts_and_banner():