add abstraction ob platform and article + vinted

"

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

platforms/base_platform.py

@@ -0,0 +1,69 @@
+from abc import ABC, abstractmethod
+
+class BasePlatform(ABC):
+    """Abstract base class for marketplace platforms"""
+    
+    def __init__(self, item_monitor):
+        """
+        Initialize platform with item monitoring configuration
+        
+        Args:
+            item_monitor: ItemMonitor instance with search parameters
+        """
+        self._item_monitor = item_monitor
+    
+    @abstractmethod
+    def get_platform_name(self):
+        """
+        Get the name of the platform
+        
+        Returns:
+            str: Platform name (e.g., 'wallapop', 'vinted', 'buyee')
+        """
+        pass
+    
+    @abstractmethod
+    def create_url(self):
+        """
+        Create the search URL based on item_monitor parameters
+        
+        Returns:
+            str: Complete URL for API/search request
+        """
+        pass
+    
+    @abstractmethod
+    def fetch_articles(self):
+        """
+        Fetch articles from the platform
+        
+        Returns:
+            list: List of Article objects
+        """
+        pass
+    
+    @abstractmethod
+    def parse_response(self, response_data):
+        """
+        Parse platform-specific response into Article objects
+        
+        Args:
+            response_data: Raw response data from the platform
+            
+        Returns:
+            list: List of Article objects
+        """
+        pass
+    
+    def get_request_headers(self):
+        """
+        Get platform-specific request headers
+        Override this method if platform needs custom headers
+        
+        Returns:
+            dict: Headers for HTTP request
+        """
+        return {
+            'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/102.0.0.0 Safari/537.36'
+        }
+