feat(ui): add mobile preview device framing and design QA tools

vibn-frontend/lib/ai/vibn-tools.ts

@@ -1449,6 +1449,23 @@ After this returns, ALWAYS call apps_deploy { uuid } to regenerate the live Trae
     },
   },
 
+  {
+    name: "request_visual_qa",
+    description:
+      "Runs a fast background AI agent to critique a UI file (like page.tsx or .css) against a strict 5-dimensional design rubric. Use this before finishing any turn that involves visual changes.",
+    parameters: {
+      type: "OBJECT",
+      properties: {
+        targetPath: {
+          type: "STRING",
+          description:
+            "The path of the file to critique, e.g. apps/web/app/page.tsx",
+        },
+      },
+      required: ["targetPath"],
+    },
+  },
+
   // ── Path B: ship to production ─────────────────────────────────────────────
 
   {