raise an error if item was using invalid preset.

app/library/ItemDTO.py

@@ -134,6 +134,12 @@ class Item:
 
         preset = item.get("preset")
         if preset and isinstance(preset, str) and preset != Item._default_preset():
+            from .Presets import Presets
+
+            if not Presets.get_instance().has(preset):
+                msg = f"Preset '{preset}' does not exist."
+                raise ValueError(msg)
+
             data["preset"] = preset
 
         if item.get("folder") and isinstance(item.get("folder"), str):

app/library/Presets.py

@@ -266,6 +266,19 @@ class Presets(metaclass=Singleton):
 
         return self
 
+    def has(self, id_or_name: str) -> bool:
+        """
+        Check if the preset exists by id or name.
+
+        Args:
+            id_or_name (str): The id or name of the preset.
+
+        Returns:
+            bool: True if the preset exists, False otherwise.
+
+        """
+        return self.get(id_or_name) is not None
+
     def get(self, id_or_name: str) -> Preset | None:
         """
         Get the preset by id or name.