feat: add ScoreRequest/ScoreResponse models and SCORE_API_TOKEN setting

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

rag_eval/settings.py

@@ -52,6 +52,11 @@ class EvaluationSettings(BaseSettings):
     )
     parser_failure_mode: str = Field(default="fail", alias="PARSER_FAILURE_MODE")
     dataset_generator_model: str | None = Field(default=None, alias="DATASET_GENERATOR_MODEL")
+    score_api_token: str | None = Field(
+        default=None,
+        alias="SCORE_API_TOKEN",
+        description="Bearer token for /api/score endpoint. Empty = no auth.",
+    )
 
     @property
     def openai_client_kwargs(self) -> dict[str, str | float]: