v3.1 + 批次0: 智能回复重构基线 - ApprovalMatcher + 关键词降级 + 文档速修 + v4.0任务书面化

backend/app/models/conversation.py

@@ -348,6 +348,25 @@ class Conversation(Base):
         comment="重开时关联的原会话ID",
     )
 
+    # ----------------------------------------------------------------------
+    # P1新增：会话归档功能（2026-07-14）
+    # ----------------------------------------------------------------------
+
+    # 是否已归档（会话结束超过90天后自动标记）
+    is_archived: Mapped[bool] = mapped_column(
+        Boolean,
+        nullable=False,
+        default=False,
+        comment="是否已归档",
+    )
+
+    # 归档时间
+    archived_at: Mapped[Optional[datetime]] = mapped_column(
+        DateTime(timezone=True),
+        nullable=True,
+        comment="归档时间",
+    )
+
     # ----------------------------------------------------------------------
     # 索引定义（和架构文档 DDL 严格一致）
     # ----------------------------------------------------------------------
@@ -367,6 +386,9 @@ class Conversation(Base):
         # P0新增：排队分层排序支持
         Index("idx_conversations_queue_priority", "queue_priority"),
         Index("idx_conversations_info_locked", "info_locked"),
+        # P1新增：会话归档查询支持
+        Index("idx_conversations_is_archived", "is_archived"),
+        Index("idx_conversations_archived_at", "archived_at"),
     )
 
     def __repr__(self) -> str: