add abstraction ob platform and article + vinted

"

Signed-off-by: Omar Sánchez Pizarro <omar.sanchez@pistacero.net>

platforms/platform_factory.py

@@ -0,0 +1,62 @@
+from platforms.wallapop_platform import WallapopPlatform
+from platforms.vinted_platform import VintedPlatform
+
+class PlatformFactory:
+    """Factory class for creating platform instances"""
+    
+    # Registry of available platforms
+    _platforms = {
+        'wallapop': WallapopPlatform,
+        'vinted': VintedPlatform,
+        # Add more platforms here as they are implemented:
+        # 'buyee': BuyeePlatform,
+    }
+    
+    @classmethod
+    def create_platform(cls, platform_name, item_monitor):
+        """
+        Create a platform instance based on the platform name
+        
+        Args:
+            platform_name: Name of the platform (e.g., 'wallapop', 'vinted')
+            item_monitor: ItemMonitor instance with search parameters
+            
+        Returns:
+            BasePlatform: Instance of the requested platform
+            
+        Raises:
+            ValueError: If platform is not supported
+        """
+        platform_name = platform_name.lower()
+        
+        if platform_name not in cls._platforms:
+            available = ', '.join(cls._platforms.keys())
+            raise ValueError(
+                f"Platform '{platform_name}' is not supported. "
+                f"Available platforms: {available}"
+            )
+        
+        platform_class = cls._platforms[platform_name]
+        return platform_class(item_monitor)
+    
+    @classmethod
+    def get_available_platforms(cls):
+        """
+        Get list of available platform names
+        
+        Returns:
+            list: List of supported platform names
+        """
+        return list(cls._platforms.keys())
+    
+    @classmethod
+    def register_platform(cls, platform_name, platform_class):
+        """
+        Register a new platform class
+        
+        Args:
+            platform_name: Name identifier for the platform
+            platform_class: Class implementing BasePlatform
+        """
+        cls._platforms[platform_name.lower()] = platform_class
+