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

.agents/skills/multi-agent-mux-monitor/scripts/reconcile.sh

@@ -520,7 +520,7 @@ if herdr_confirmed:
         agent = None
         role = 'creator'
         for r_name in ('creator', 'planner', 'reviewer'):
-            for a_name in ('claude', 'agy', 'hermes', 'grok', 'opencode'):
+            for a_name in ('claude', 'agy', 'hermes', 'grok', 'opencode', 'codex'):
                 if name.endswith(f"-{r_name}-{a_name}"):
                     role = r_name
                     agent = a_name
@@ -539,7 +539,7 @@ if herdr_confirmed:
                         if tok.startswith('MAM_MANAGED='):
                             managed_path = tok.split('=', 1)[1]
                             if os.path.realpath(managed_path) == os.path.realpath(workspace_root):
-                                for a_name in ('claude', 'agy', 'hermes', 'grok', 'opencode'):
+                                for a_name in ('claude', 'agy', 'hermes', 'grok', 'opencode', 'codex'):
                                     if a_name in pm_check.get('cmd', '') or a_name in pm_check.get('cmd_full', ''):
                                         agent = a_name
                                         break
@@ -547,6 +547,10 @@ if herdr_confirmed:
                 except Exception:
                     pass
 
+        if not agent:
+            if pm_check and pm_check.get('cmd') in ('claude', 'agy', 'hermes', 'grok', 'opencode', 'codex'):
+                agent = pm_check['cmd']
+
         if not agent:
             continue
 
@@ -603,6 +607,9 @@ if herdr_confirmed:
         elif agent == 'opencode':
             entry['child_pid'] = 0
             entry['opencode_session_id_own'] = None
+        elif agent == 'codex':
+            entry['child_pid'] = 0
+            entry['codex_session_id_own'] = None
         d.setdefault('herdr_sessions', []).append(entry)
         yaml_session_names.add(name)
         drifts.append({'class': 'B', 'name': name,
@@ -613,7 +620,7 @@ def row_agent(s):
     return agent_of_row(s)
 
 OWN_KEY_BY_AGENT = {
-    a: _get_own_key(a) for a in ('claude', 'agy', 'hermes', 'grok', 'opencode')
+    a: _get_own_key(a) for a in ('claude', 'agy', 'hermes', 'grok', 'opencode', 'codex')
 }
 
 # === drift C0: 지정된 ID 는 발견이 아니라 '확인'만 필요하다 ===
@@ -896,6 +903,88 @@ for s in d.get('herdr_sessions', []):
         else:
             _pin_and_verify_resume(s, 'opencode', cwd, uuid, degraded=True)
 
+# === drift C (codex): codex 새 session id materialize (per-row own id) ===
+for s in d.get('herdr_sessions', []):
+    if row_agent(s) != 'codex':
+        continue
+    if s.get('status') != 'running':
+        continue
+    if s.get('codex_session_id_own'):
+        continue
+    cwd = (s.get('pane') or {}).get('cwd', '')
+    if not cwd:
+        continue
+
+    codex_home = os.environ.get('CODEX_HOME') or f"{home}/.codex"
+    epoch_threshold = s.get('herdr_session_epoch', 0)
+
+    sibling_claimed = [
+        other.get('codex_session_id_own')
+        for other in d.get('herdr_sessions', [])
+        if other is not s
+        and (other.get('pane') or {}).get('cwd') == cwd
+        and other.get('status') not in ('stopped', 'terminated')
+        and other.get('codex_session_id_own')
+    ]
+    s_eval = dict(s)
+    s_eval['_sibling_claimed_uuids'] = sibling_claimed
+
+    valid_candidates = []
+    try:
+        # Rev.2: state DB first (indexed, single query) — dynamic filename,
+        # no hardcoded suffix (see §1.5 / §2 _state_db()).
+        state_matches = glob.glob(f"{codex_home}/state_*.sqlite")
+        state_db = max(state_matches, key=os.path.getmtime) if state_matches else None
+        rows = []
+        if state_db and os.path.exists(state_db):
+            try:
+                conn = sqlite3.connect(state_db)
+                cols = [c[1] for c in conn.execute("PRAGMA table_info(threads)").fetchall()]
+                order_col = "updated_at" if "updated_at" in cols else ("created_at" if "created_at" in cols else None)
+                if order_col:
+                    rows = conn.execute(
+                        f"SELECT id, {order_col} FROM threads WHERE cwd=? ORDER BY {order_col} DESC LIMIT 20",
+                        (cwd,)
+                    ).fetchall()
+                else:
+                    rows = [(r[0], int(time.time())) for r in conn.execute("SELECT id FROM threads WHERE cwd=? LIMIT 20", (cwd,)).fetchall()]
+                conn.close()
+            except Exception:
+                rows = []
+        if not rows:
+            # Fallback: bounded glob over the date-nested tree
+            paths = sorted(
+                glob.glob(f"{codex_home}/sessions/*/*/*/rollout-*.jsonl"),
+                key=os.path.getmtime, reverse=True
+            )[:50]
+            rows = [(os.path.basename(p)[:-6][-36:], os.path.getmtime(p)) for p in paths]
+
+        for uuid, ts in rows:
+            if epoch_threshold and ts and ts < epoch_threshold:
+                continue
+            if uuid in (sibling_claimed or []):
+                continue
+            if verify_session_uuid(cwd, 'codex', uuid, s_eval, mode="discover"):
+                valid_candidates.append(uuid)
+    except Exception:
+        pass
+
+    if len(valid_candidates) > 1:
+        drifts.append({'class': 'C-ambiguous', 'name': s['name'],
+                       'msg': f"{s['name']}: {len(valid_candidates)} candidate transcripts newer than session epoch; not pinning"})
+        s['last_visible_status'] = f"ambiguous: {len(valid_candidates)} candidates"
+        actions.append(f"ambiguous candidates: {s['name']}")
+    elif len(valid_candidates) == 1:
+        uuid = valid_candidates[0]
+        cmd = ['bash', '-c', f'source "{lib_sh}" && verify_tui_viewport "{s["name"]}" "codex" "{cwd}"']
+        rc = subprocess.run(cmd).returncode
+        if rc == 0:
+            _pin_and_verify_resume(s, 'codex', cwd, uuid, degraded=False)
+        elif rc == 1:
+            drifts.append({'class': 'C-warn', 'name': s['name'], 'msg': f"{s['name']}: TUI viewport mismatch for candidate {uuid} — not pinned, will retry next cycle"})
+        else:
+            _pin_and_verify_resume(s, 'codex', cwd, uuid, degraded=True)
+
 result = {
     'timestamp': now_iso,
     'yaml_path': yaml_path,