Add Codex support for qa plugin (dual-host, no MCP)

.agents/plugins/marketplace.json

@@ -0,0 +1,19 @@
+{
+  "name": "browser-use",
+  "interface": {
+    "displayName": "Browser Use"
+  },
+  "plugins": [
+    {
+      "name": "qa",
+      "source": {
+        "source": "local",
+        "path": "./qa"
+      },
+      "policy": {
+        "installation": "AVAILABLE"
+      },
+      "category": "Productivity"
+    }
+  ]
+}

qa/.codex-plugin/plugin.json

@@ -0,0 +1,17 @@
+{
+  "name": "qa",
+  "version": "0.1.0",
+  "description": "QA-test any website or app with a real browser and return a 1-5 score with evidence. Drives a Browser Use cloud browser (tunnels localhost automatically). Requires the browser-harness CLI.",
+  "author": {
+    "name": "Browser Use",
+    "url": "https://browser-use.com"
+  },
+  "skills": "./skills/",
+  "interface": {
+    "displayName": "QA",
+    "shortDescription": "QA-test a site or app and return a 1-5 score with evidence.",
+    "longDescription": "Drives a real Browser Use cloud browser to test a website or app and return a 1-5 quality score (5 = flawless, 1 = broken) with evidence. Tunnels a localhost dev server automatically. Run as /qa <url-or-localhost-port>. Requires the browser-harness CLI (a one-time uv/pip install).",
+    "category": "Productivity",
+    "websiteURL": "https://browser-use.com"
+  }
+}

qa/skills/qa/SKILL.md

@@ -26,7 +26,7 @@ PY
 ```
 
 If `browser-harness` is **not** on `PATH`, stop and tell the user to install it, then resume:
-- Plugin: `claude plugin install browser-harness@browser-use`
+- Plugin: install the `browser-harness` plugin for your agent — `claude plugin install browser-harness@browser-use` (Claude Code) or `codex plugin add browser-harness@browser-use` (Codex)
 - CLI (one-time): see the browser-harness skill's `references/install.md` (it's a `uv`/pip install of the `browser-harness` package). Repo: https://github.com/browser-use/browser-harness
 
 Do not attempt to QA with anything other than browser-harness + a cloud browser.