Add missing LicenseStats model to fix import error

Author: VoxHash

licensechain/models.py

@@ -164,6 +164,17 @@ def previous_page(self) -> Optional[int]:
         return self.page - 1 if self.has_previous_page else None
 
 
+class LicenseStats(BaseLicenseChainModel):
+    """License statistics model."""
+    
+    total: int = 0
+    active: int = 0
+    expired: int = 0
+    revoked: int = 0
+    suspended: int = 0
+    revenue: float = 0.0
+
+
 class ValidationResult(BaseLicenseChainModel):
     """License validation result model."""