fix: restrict __setattr__ range handling to declared model fields

- Only apply _handle_value for fields in model_fields (v2) / __fields__ (v1)
- Prevents range handling from intercepting private attrs, __dict__,
  __pydantic_private__, and controller-added fields

Author: simontaurus

src/oold/model/__init__.py

@@ -622,11 +622,8 @@ def _handle_value(self, name, value):
 
     def __setattr__(self, name, value, internal=False):
         # print("__setattr__", name, value)
-        if not internal and name not in [
-            "__dict__",
-            "__pydantic_private__",
-            "__iris__",
-        ]:
+        # Only apply range handling for declared model fields
+        if not internal and name in self.model_fields:
             value = self._handle_value(name, value)
 
         return super().__setattr__(name, value)

src/oold/model/v1/__init__.py

@@ -538,11 +538,8 @@ def _handle_value(self, name, value):
 
     def __setattr__(self, name, value, internal=False):
         # print("__setattr__", name, value)
-        if not internal and name not in [
-            "__dict__",
-            "__pydantic_private__",
-            "__iris__",
-        ]:
+        # Only apply range handling for declared model fields
+        if not internal and name in self.__fields__:
             value = self._handle_value(name, value)
 
         return super().__setattr__(name, value)