feat: add arty script to fix DiffRhythm transformers version

Adds 'fix/diffrhythm-transformers' command to quickly downgrade
transformers library to 4.49.0 for DiffRhythm compatibility.

Usage: arty fix/diffrhythm-transformers

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

arty.yml

@@ -396,6 +396,38 @@ scripts:
     echo ""
     echo "Category: 🌸Pivoine/Audio"
 
+  fix/diffrhythm-transformers: |
+    echo "========================================="
+    echo "  Fix DiffRhythm Transformers Version"
+    echo "========================================="
+    echo ""
+    echo "Issue: Tensor dimension mismatch (32 vs 64) in rotary embeddings"
+    echo "Solution: Downgrade transformers to 4.49.0"
+    echo ""
+    echo "References:"
+    echo "  - https://github.com/billwuhao/ComfyUI_DiffRhythm/issues/44"
+    echo "  - https://github.com/billwuhao/ComfyUI_DiffRhythm/issues/48"
+    echo ""
+
+    cd /workspace/ComfyUI
+    source venv/bin/activate
+
+    echo "Current transformers version:"
+    pip show transformers | grep Version
+    echo ""
+
+    echo "Installing transformers==4.49.0..."
+    pip install transformers==4.49.0
+
+    echo ""
+    echo "✓ Transformers downgraded to 4.49.0"
+    echo ""
+    echo "Next steps:"
+    echo "  1. Restart ComfyUI: arty services/comfyui/restart"
+    echo "  2. Test DiffRhythm workflows"
+
+    deactivate
+
   setup/comfyui-extensions-deps: |
     echo "========================================="
     echo "  Installing ComfyUI Extensions Dependencies"