Update API docs: document judge_language in all score endpoints

- POST /api/score: add judge_language section with default/usage

- POST /api/score/async: mention judge_language in docstring

- POST /api/score/session_async: add to description string + JSON example

- ScoreRequest / SessionScoreRequest: add judge_language to schema example

- request_summary snapshots: include judge_language for observability

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

webapp/models.py

@@ -443,6 +443,7 @@ class ScoreRequest(BaseModel):
                 ],
                 "judge_model": "gpt-5",
                 "embedding_model": "text-embedding-3-small",
+                "judge_language": "zh",
             }
         }
     )
@@ -573,6 +574,7 @@ class SessionScoreRequest(ScoreRequest):
                         "metrics": ["answer_relevancy", "faithfulness"],
                         "judge_model": "gpt-5.5",
                         "embedding_model": "text-embedding-3-small",
+                        "judge_language": "zh",
                     },
                 }
             ]