Add missing UserStats model

Author: VoxHash

licensechain/models.py

@@ -175,6 +175,14 @@ class LicenseStats(BaseLicenseChainModel):
     revenue: float = 0.0
 
 
+class UserStats(BaseLicenseChainModel):
+    """User statistics model."""
+    
+    total: int = 0
+    active: int = 0
+    inactive: int = 0
+
+
 class ValidationResult(BaseLicenseChainModel):
     """License validation result model."""