feat: Add Advoware History and Watcher services for document synchronization

- Implement AdvowareHistoryService for fetching and creating history entries.
- Implement AdvowareWatcherService for file operations including listing, downloading, and uploading with Blake3 hash verification.
- Introduce Blake3 utility functions for hash computation and verification.
- Create document sync cron step to poll Redis for pending Aktennummern and emit sync events.
- Develop document sync event handler to manage 3-way merge synchronization for Akten, including metadata updates and error handling.

services/advoware_service.py

@@ -127,3 +127,35 @@ class AdvowareService:
             # Expected: 403 Forbidden
             self._log(f"[ADVO] DELETE not allowed (expected): {e}", level='warning')
             return False
+    
+    # ========== AKTEN ==========
+    
+    async def get_akte(self, akte_id: int) -> Optional[Dict[str, Any]]:
+        """
+        Get Akte details including ablage status.
+        
+        Args:
+            akte_id: Advoware Akte ID
+            
+        Returns:
+            Akte details with fields:
+            - ablage: int (0 or 1, archive status)
+            - az: str (Aktenzeichen)
+            - rubrum: str
+            - referat: str
+            - wegen: str
+            
+            Returns None if Akte not found
+        """
+        try:
+            endpoint = f"api/v1/advonet/Akten/{akte_id}"
+            result = await self.api.api_call(endpoint, method='GET')
+            
+            if result:
+                self._log(f"[ADVO] ✅ Fetched Akte {akte_id}: {result.get('az', 'N/A')}")
+            
+            return result
+        
+        except Exception as e:
+            self._log(f"[ADVO] Error loading Akte {akte_id}: {e}", level='error')
+            return None