docs(codex): document harness command smoke

docs/help/testing.md

@@ -399,6 +399,8 @@ Docker notes:
   - send a first gateway agent turn to `codex/gpt-5.4`
   - send a second turn to the same OpenClaw session and verify the app-server
     thread can resume
+  - run `/codex status` and `/codex models` through the same gateway command
+    path
 - Test: `src/gateway/gateway-codex-harness.live.test.ts`
 - Enable: `OPENCLAW_LIVE_CODEX_HARNESS=1`
 - Default model: `codex/gpt-5.4`

docs/plugins/codex-harness.md

@@ -438,6 +438,10 @@ normal turns. On the next message, OpenClaw resumes that Codex thread, passes th
 currently selected OpenClaw `codex/*` model into app-server, and keeps extended
 history enabled.
 
+The command surface requires Codex app-server `0.118.0` or newer. Individual
+control methods are reported as `unsupported by this Codex app-server` if a
+future or custom app-server does not expose that JSON-RPC method.
+
 ## Tools, media, and compaction
 
 The Codex harness changes the low-level embedded agent executor only.