chore: initialize medical consultation agent demo

backend/app/repositories/evaluation_repository.py

@@ -0,0 +1,46 @@
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+
+from app.models.training_record import TrainingRecord
+
+
+class EvaluationRepository:
+    """评价仓储：负责完整训练结束后的 training_record 读写。"""
+
+    def __init__(self, db: Session) -> None:
+        self.db = db
+
+    def create_record(self, record: TrainingRecord) -> TrainingRecord:
+        """评价保存：把 AI 评分报告保存为训练记录。"""
+        self.db.add(record)
+        self.db.flush()
+        return record
+
+    def get_by_session(self, session_id: int, user_id: str) -> TrainingRecord | None:
+        """评价读取：按会话 ID 和外部 user_id 查询训练记录。"""
+        stmt = select(TrainingRecord).where(
+            TrainingRecord.session_id == session_id,
+            TrainingRecord.external_user_id == user_id,
+        )
+        return self.db.scalar(stmt)
+
+    def get_owned_record(self, evaluation_id: int, user_id: str) -> TrainingRecord | None:
+        """评价归属校验：按训练记录 ID 和外部 user_id 查询记录。"""
+        stmt = select(TrainingRecord).where(
+            TrainingRecord.id == evaluation_id,
+            TrainingRecord.external_user_id == user_id,
+        )
+        return self.db.scalar(stmt)
+
+    def list_by_user(self, user_id: str) -> list[TrainingRecord]:
+        """历史评价：按外部 user_id 查询完整训练后的评价记录。"""
+        stmt = (
+            select(TrainingRecord)
+            .where(TrainingRecord.external_user_id == user_id)
+            .order_by(TrainingRecord.created_at.desc())
+        )
+        return list(self.db.scalars(stmt).all())
+
+    def flush(self) -> None:
+        """记录更新：刷新 PDF 路径等派生字段。"""
+        self.db.flush()