Fix LoRA import - Handle ZIP files with metadata at root level

- Support two ZIP structures:
1. metadata.json at root (direct export from training)
2. metadata.json in subfolder (exported via download button)

- Read lora_name from metadata.json when at root level
- Better logging for import process
- Handle duplicate names with timestamp suffix
- Improved error message when no valid LoRA found

Fixes: 'No valid LoRA adapter found in zip file' when uploading
trained LoRAs with metadata.json at root

backend/services/lora_training_service.py

@@ -669,16 +669,28 @@ class LoRATrainingService:
                 with zipfile.ZipFile(zip_path, 'r') as zip_ref:
                     zip_ref.extractall(temp_dir)
                 
-                # Find the LoRA folder (should have metadata.json)
                 temp_path = Path(temp_dir)
-                lora_folders = [d for d in temp_path.iterdir() if d.is_dir() and (d / "metadata.json").exists()]
                 
-                if not lora_folders:
-                    logger.error("No valid LoRA adapter found in zip file")
-                    return None
-                
-                source_dir = lora_folders[0]
-                lora_name = source_dir.name
+                # Case 1: Check if metadata.json is at root level
+                if (temp_path / "metadata.json").exists():
+                    logger.info("Found metadata.json at root level")
+                    source_dir = temp_path
+                    
+                    # Read metadata to get LoRA name
+                    with open(temp_path / "metadata.json", 'r') as f:
+                        metadata = json.load(f)
+                        lora_name = metadata.get('lora_name', 'imported_lora')
+                else:
+                    # Case 2: Look for a subfolder with metadata.json
+                    lora_folders = [d for d in temp_path.iterdir() if d.is_dir() and (d / "metadata.json").exists()]
+                    
+                    if not lora_folders:
+                        logger.error("No valid LoRA adapter found in zip file. Expected metadata.json at root or in a subfolder.")
+                        return None
+                    
+                    source_dir = lora_folders[0]
+                    lora_name = source_dir.name
+                    logger.info(f"Found LoRA in subfolder: {lora_name}")
                 
                 # Copy to loras directory
                 dest_path = self.lora_dir / lora_name
@@ -686,14 +698,24 @@ class LoRATrainingService:
                 # If already exists, rename with timestamp
                 if dest_path.exists():
                     timestamp = int(time.time())
+                    original_name = lora_name
                     lora_name = f"{lora_name}_{timestamp}"
                     dest_path = self.lora_dir / lora_name
+                    logger.info(f"LoRA '{original_name}' already exists, importing as '{lora_name}'")
+                
+                # Create destination directory
+                dest_path.mkdir(parents=True, exist_ok=True)
                 
-                shutil.copytree(source_dir, dest_path)
+                # Copy all files from source to destination
+                for item in source_dir.iterdir():
+                    if item.is_file():
+                        shutil.copy2(item, dest_path / item.name)
+                    elif item.is_dir():
+                        shutil.copytree(item, dest_path / item.name)
                 
-                logger.info(f"Imported LoRA adapter: {lora_name}")
+                logger.info(f"✅ Imported LoRA adapter: {lora_name}")
                 return lora_name
                 
         except Exception as e:
-            logger.error(f"Failed to import LoRA adapter: {str(e)}")
+            logger.error(f"Failed to import LoRA adapter: {str(e)}", exc_info=True)
             return None