Refactor code structure; improve organization and readability across multiple files

models/inventory.py

@@ -69,3 +69,21 @@ class Inventory(db.Model):
             return f"Serial: {self.serial}"
         else:
             return f"ID: {self.id}"
+        
+    def serialize(self) -> dict[str, Any]:
+        return {
+            'id': self.id,
+            'timestamp': self.timestamp.isoformat() if self.timestamp else None,
+            'condition': self.condition,
+            'needed': self.needed,
+            'type_id': self.type_id,
+            'inventory_name': self.inventory_name,
+            'serial': self.serial,
+            'model': self.model,
+            'notes': self.notes,
+            'owner_id': self.owner_id,
+            'brand_id': self.brand_id,
+            'location_id': self.location_id,
+            'barcode': self.barcode,
+            'shared': self.shared
+        }