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

docs/NEW_AGENT_INTEGRATION_GUIDE.md

@@ -265,7 +265,7 @@ def test_adapter_required_properties():
 | 에이전트 백엔드 | 세션 저장소 형식 | 인증 방식 | 프롬프트 감지 난이도 | 난이도 Tier | 예상 소요 공수 |
 | :--- | :--- | :--- | :--- | :---: | :---: |
 | **OpenCode** | `~/.local/share/opencode/` (SQLite, `opencode db path`) | 멀티 Provider Key / `auth.json` | 쉬움 (`OpenCode\|Chat`) | **Tier 1 (낮음)** | **~1.0일** |
-| **Codex CLI** | `~/.codex/projects/*.jsonl` | `OPENAI_API_KEY` | 쉬움 (`Codex\|❯`) | **Tier 1 (낮음)** | **~0.5일** |
+| **Codex CLI** | `~/.codex/sessions/*/*/*/rollout-*.jsonl` (SQLite `state_*.sqlite`) | `auth.json` / `OPENAI_API_KEY` | 쉬움 (`Codex\|Ask Codex to do anything`) | **v4.2.0 완료** | **완료** |
 | **Kimi CLI** | `~/.kimi/history.db` (SQLite) | `~/.kimi/config` | 쉬움 (`Moonshot\|Kimi`) | **Tier 1 (낮음)** | **~0.5일** |
 | **Grok-Build** | `~/.grok/sessions/*.json` | 토큰 파일 / Env | 쉬움 (`Grok\|Building`) | **Tier 1 (낮음)** | **~0.5일** |
 | **Cursor CLI** | `~/.cursor/` (Headless/RPC) | OAuth / 쿠키 | 보통 (RPC 포트/상태 파싱) | **Tier 2 (중간)** | **~1.5일** |