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-resume/scripts/resolve_session_id.sh

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 # resolve_session_id.sh — multi-agent-mux-resume 의 부속 스크립트
 # Usage:
-#   bash resolve_session_id.sh --workspace <path> --agent <claude|agy|hermes|grok|opencode>
+#   bash resolve_session_id.sh --workspace <path> --agent <claude|agy|hermes|grok|opencode|codex>
 # 출력: stdout 으로 UUID 한 줄 (없으면 빈 줄 + exit 0)
 #
 # P0-C: 전역 agent_identities 를 즉시 반환하지 않는다. lib.sh::find_workspace_uuid
@@ -13,7 +13,7 @@ source "$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)/lib.sh"
 
 usage() {
   cat <<EOF
-Usage: $0 --workspace <path> --agent <claude|agy|hermes|grok|opencode> [--session <name>]
+Usage: $0 --workspace <path> --agent <claude|agy|hermes|grok|opencode|codex> [--session <name>]
 Outputs the resolved UUID on stdout (empty if not found).
 --session prefers that registry row's recorded id; falls back to workspace-wide discovery if it does not verify.
 EOF
@@ -36,8 +36,8 @@ done
 [ -n "$WORKSPACE" ] || { echo "ERROR: --workspace required" >&2; exit 2; }
 [ -n "$AGENT" ]    || { echo "ERROR: --agent required" >&2; exit 2; }
 case "$AGENT" in
-  claude|agy|hermes|grok|opencode) ;;
-  *) echo "ERROR: --agent must be claude, agy, hermes, grok, or opencode" >&2; exit 2 ;;
+  claude|agy|hermes|grok|opencode|codex) ;;
+  *) echo "ERROR: --agent must be claude, agy, hermes, grok, opencode, or codex" >&2; exit 2 ;;
 esac
 
 find_workspace_uuid "$WORKSPACE" "$AGENT" "$SESSION_NAME"