refactor: Use typing.Self for disabled() return type, remove redundant overrides

The base AIConfigDefault.disabled() already uses cls(), so subclass
overrides were unnecessary. Use Self return type annotation for
correct narrowing and remove the three identical overrides from
AICompletionConfigDefault, AIAgentConfigDefault, AIJudgeConfigDefault.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: jsonbailey

packages/sdk/server-ai/src/ldai/models.py

@@ -1,7 +1,14 @@
+from __future__ import annotations
+
 import warnings
 from dataclasses import dataclass, field
 from typing import Any, Callable, Dict, List, Literal, Optional, Union
 
+try:
+    from typing import Self
+except ImportError:
+    from typing_extensions import Self
+
 
 @dataclass
 class LDMessage:
@@ -151,7 +158,7 @@ class AIConfigDefault:
     provider: Optional[ProviderConfig] = None
 
     @classmethod
-    def disabled(cls) -> 'AIConfigDefault':
+    def disabled(cls) -> Self:
         return cls(enabled=False)
 
     def _base_to_dict(self) -> Dict[str, Any]:
@@ -207,10 +214,6 @@ class AICompletionConfigDefault(AIConfigDefault):
     messages: Optional[List[LDMessage]] = None
     judge_configuration: Optional[JudgeConfiguration] = None
 
-    @classmethod
-    def disabled(cls) -> 'AICompletionConfigDefault':
-        return cls(enabled=False)
-
     def to_dict(self) -> dict:
         """
         Render the given default values as an AICompletionConfigDefault-compatible dictionary object.
@@ -253,10 +256,6 @@ class AIAgentConfigDefault(AIConfigDefault):
     instructions: Optional[str] = None
     judge_configuration: Optional[JudgeConfiguration] = None
 
-    @classmethod
-    def disabled(cls) -> 'AIAgentConfigDefault':
-        return cls(enabled=False)
-
     def to_dict(self) -> Dict[str, Any]:
         """
         Render the given agent config default as a dictionary object.
@@ -303,10 +302,6 @@ class AIJudgeConfigDefault(AIConfigDefault):
     evaluation_metric_keys: Optional[List[str]] = None
     evaluation_metric_key: Optional[str] = None
 
-    @classmethod
-    def disabled(cls) -> 'AIJudgeConfigDefault':
-        return cls(enabled=False)
-
     def to_dict(self) -> dict:
         """
         Render the given judge config default as a dictionary object.