fix: CI pipeline clones repo to /workspace directly, not subdir

.cnb.yml

@@ -15,11 +15,9 @@ master:
         - name: train
           script: |
             set -e
-            echo "=== 开始训练 ==="
+            echo "=== 小狸AI训练开始 ==="
             cd /workspace
-            ls -la
-            cd /workspace/xiaoli-llm-chat
             nvidia-smi
-            echo "=== 启动训练 ==="
+            echo "=== GPU就绪,启动训练 ==="
             python3 scripts/train_cnb.py --epochs 100 --batch_size 16
             echo "=== 训练完成 ==="