Feature/actr forget (#55)

* [changes]Request to remove 'config_id' has been received.

* [add]Add the access history record table

* [changes]Request to remove 'config_id' has been received.

* [add]Add the access history record table

* [add]Obtain the record of the forgetting trend

* [changes]Based on the AI's suggestion, make the necessary modifications.

api/app/models/forgetting_cycle_history_model.py

@@ -0,0 +1,40 @@
+"""
+遗忘周期历史记录模型
+
+用于存储每次遗忘周期执行的历史数据，支持趋势分析和可视化。
+"""
+
+import uuid
+from datetime import datetime
+from sqlalchemy import Column, Integer, String, Float, DateTime, Index
+from sqlalchemy.dialects.postgresql import UUID
+from app.db import Base
+
+
+class ForgettingCycleHistory(Base):
+    """遗忘周期历史记录表"""
+    
+    __tablename__ = "forgetting_cycle_history"
+    
+    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4, nullable=False, index=True, comment="主键ID")
+    end_user_id = Column(String(255), nullable=False, comment="终端用户ID")
+    execution_time = Column(DateTime, nullable=False, default=datetime.now, comment="执行时间")
+    merged_count = Column(Integer, default=0, comment="本次成功融合的节点对数")
+    failed_count = Column(Integer, default=0, comment="本次融合失败的节点对数")
+    average_activation_value = Column(Float, nullable=True, comment="平均激活值")
+    total_nodes = Column(Integer, default=0, comment="总节点数")
+    low_activation_nodes = Column(Integer, default=0, comment="低于遗忘阈值的节点总数（包含已融合、失败和待处理的）")
+    duration_seconds = Column(Float, nullable=True, comment="执行耗时（秒）")
+    trigger_type = Column(String(50), default="manual", comment="触发类型: manual/scheduled")
+    
+    # 创建索引以优化查询
+    __table_args__ = (
+        Index('idx_end_user_time', 'end_user_id', 'execution_time'),
+        Index('idx_execution_time', 'execution_time'),
+    )
+    
+    def __repr__(self):
+        return (
+            f"<ForgettingCycleHistory(id={self.id}, end_user_id={self.end_user_id}, "
+            f"merged_count={self.merged_count}, execution_time={self.execution_time})>"
+        )