feat: add native Codex hook integration

README.md

@@ -73,6 +73,8 @@ elydora install \
   --kid agent-456-key-v1
 ```
 
+Codex performs a one-time trust review for user hooks. Run `/hooks` in Codex after installation and trust the Elydora `PreToolUse` and `PostToolUse` definitions.
+
 Kiro CLI installation covers both runtime contracts. Kiro CLI v2 uses the generated custom agent through `kiro-cli --agent elydora-audit`. Kiro CLI v3 loads the global standalone hooks when started with `kiro-cli --v3`.
 
 ### Commands
@@ -89,6 +91,7 @@ Kiro CLI installation covers both runtime contracts. Kiro CLI v2 uses the genera
 | Agent | Key |
 |-------|-----|
 | Claude Code | `claudecode` |
+| OpenAI Codex | `codex` |
 | Copilot CLI | `copilot` |
 | Cursor | `cursor` |
 | Gemini CLI | `gemini` |