Enhance node processing and error handling in workflow mappers

- Improved reference handling in NodeMapper to support integer node IDs and added error logging for reference processing failures.
- Updated LoraLoaderMapper and LoraStackerMapper to handle lora_stack as a dictionary, ensuring compatibility with new data formats.
- Refactored trace_model_path utility to perform a depth-first search for LoRA nodes, improving the accuracy of model path tracing.
- Cleaned up unused code in parser.py related to LoRA processing, streamlining the workflow parsing logic.

test_parser.py

@@ -0,0 +1,45 @@
+import json
+import sys
+from py.workflow.parser import WorkflowParser
+from py.workflow.utils import trace_model_path
+
+# Load workflow data
+with open('refs/prompt.json', 'r') as f:
+    workflow_data = json.load(f)
+
+# Parse workflow
+parser = WorkflowParser()
+try:
+    # Find KSampler node
+    ksampler_node = None
+    for node_id, node in workflow_data.items():
+        if node.get("class_type") == "KSampler":
+            ksampler_node = node_id
+            break
+    
+    if not ksampler_node:
+        print("KSampler node not found")
+        sys.exit(1)
+    
+    # Trace all Lora nodes
+    print("Finding Lora nodes in the workflow...")
+    lora_nodes = trace_model_path(workflow_data, ksampler_node)
+    print(f"Found Lora nodes: {lora_nodes}")
+    
+    # Print node details
+    for node_id in lora_nodes:
+        node = workflow_data[node_id]
+        print(f"\nNode {node_id}: {node.get('class_type')}")
+        for key, value in node.get("inputs", {}).items():
+            print(f"  - {key}: {value}")
+    
+    # Parse the workflow
+    result = parser.parse_workflow(workflow_data)
+    print("\nParsing successful!")
+    print(json.dumps(result, indent=2))
+    sys.exit(0)
+except Exception as e:
+    print(f"Error parsing workflow: {e}")
+    import traceback
+    traceback.print_exc()
+    sys.exit(1)