feat(debug): replace websocket with ComfyUI UI system for metadata display

- Update DebugMetadata node to return metadata via ComfyUI's UI system instead of websocket
- Add new JsonDisplayWidget Vue component for displaying metadata in the UI
- Remove dependency on PromptServer and websocket communication
- Improve error handling with proper UI feedback
- Maintain backward compatibility with existing metadata collection system

py/nodes/debug_metadata.py

@@ -1,15 +1,15 @@
 import logging
-from server import PromptServer   # type: ignore
 from ..metadata_collector.metadata_processor import MetadataProcessor
 
 logger = logging.getLogger(__name__)
 
+
 class DebugMetadata:
     NAME = "Debug Metadata (LoraManager)"
     CATEGORY = "Lora Manager/utils"
     DESCRIPTION = "Debug node to verify metadata_processor functionality"
     OUTPUT_NODE = True
-    
+
     @classmethod
     def INPUT_TYPES(cls):
         return {
@@ -25,21 +25,37 @@ class DebugMetadata:
     FUNCTION = "process_metadata"
 
     def process_metadata(self, images, id):
+        """
+        Process metadata from the execution context and return it for UI display.
+
+        The metadata is returned via the 'ui' key in the return dict, which triggers
+        node.onExecuted on the frontend to update the JsonDisplayWidget.
+
+        Args:
+            images: Input images (required for execution flow)
+            id: Node's unique ID (hidden)
+
+        Returns:
+            Dict with 'result' (empty tuple) and 'ui' (metadata dict for widget display)
+        """
         try:
             # Get the current execution context's metadata
             from ..metadata_collector import get_metadata
+
             metadata = get_metadata()
-            
-            # Use the MetadataProcessor to convert it to JSON string
-            metadata_json = MetadataProcessor.to_json(metadata, id)
-            
-            # Send metadata to frontend for display
-            PromptServer.instance.send_sync("metadata_update", {
-                "id": id,
-                "metadata": metadata_json
-            })
-            
+
+            # Use the MetadataProcessor to convert it to dict
+            metadata_dict = MetadataProcessor.to_dict(metadata, id)
+
+            return {
+                "result": (),
+                # ComfyUI expects ui values to be lists, wrap the dict in a list
+                "ui": {"metadata": [metadata_dict]},
+            }
+
         except Exception as e:
             logger.error(f"Error processing metadata: {e}")
-        
-        return ()
+            return {
+                "result": (),
+                "ui": {"metadata": [{"error": str(e)}]},
+            }