docs: update project docs and evaluation history pagination

app/repositories/evaluation_repository.py

@@ -1,4 +1,4 @@
-from sqlalchemy import delete, select
+from sqlalchemy import delete, func, select
 from sqlalchemy.orm import Session
 
 from app.models.training_record import TrainingRecord, TrainingScoreDetail
@@ -46,12 +46,19 @@ class EvaluationRepository:
         )
         return self.db.scalar(stmt)
 
-    def list_by_user(self, user_id: str) -> list[TrainingRecord]:
+    def count_by_user(self, user_id: str) -> int:
+        """历史评价计数：按外部 user_id 统计完整训练后的评价记录总数。"""
+        stmt = select(func.count()).select_from(TrainingRecord).where(TrainingRecord.external_user_id == user_id)
+        return int(self.db.scalar(stmt) or 0)
+
+    def list_by_user(self, user_id: str, limit: int, offset: int) -> 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())
+            .limit(limit)
+            .offset(offset)
         )
         return list(self.db.scalars(stmt).all())