Add GPU check as first cell in notebook

Unsloth_Studio_Colab.ipynb

@@ -1,5 +1,32 @@
 {
  "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "447c1156",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# ===========================================\n",
+    "# ⚠️  GPU Check - Run This First!\n",
+    "# ===========================================\n",
+    "import torch\n",
+    "\n",
+    "print(\"🔍 Checking for GPU...\")\n",
+    "if not torch.cuda.is_available():\n",
+    "    print(\"❌ ERROR: No GPU detected!\")\n",
+    "    print(\"\\n📋 To enable GPU:\")\n",
+    "    print(\"   1. Go to: Runtime → Change runtime type\")\n",
+    "    print(\"   2. Select: Hardware accelerator → GPU (T4 is free)\")\n",
+    "    print(\"   3. Click: Save\")\n",
+    "    print(\"   4. Restart and re-run all cells\")\n",
+    "    raise RuntimeError(\"⛔ GPU required for Unsloth Studio\")\n",
+    "else:\n",
+    "    gpu_name = torch.cuda.get_device_name(0)\n",
+    "    print(f\"✅ GPU detected: {gpu_name}\")\n",
+    "    print(\"   Ready to proceed!\")"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,