feat: 对话历史页面租户分组展示功能

- 新增 ConversationHistoryManager.get_tenant_summary() 按租户聚合会话统计
- get_sessions_paginated() 和 get_conversation_analytics() 增加 tenant_id 过滤
- 新增 GET /api/conversations/tenants 租户汇总端点
- sessions 和 analytics API 端点支持 tenant_id 查询参数
- 前端实现租户卡片列表视图和租户详情会话表格视图
- 实现面包屑导航、搜索范围限定、统计面板上下文切换
- 会话删除后自动检测空租户并返回列表视图
- dashboard.html 添加租户视图 DOM 容器
- 交互模式与知识库租户分组视图保持一致

src/core/models.py

@@ -1,4 +1,4 @@
-from sqlalchemy import Column, Integer, String, Text, DateTime, Float, Boolean, ForeignKey
+from sqlalchemy import Column, Integer, String, Text, DateTime, Float, Boolean, ForeignKey, Index
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy.orm import relationship
 from datetime import datetime
@@ -6,11 +6,15 @@ import hashlib
 
 Base = declarative_base()
 
+# 默认租户ID，单租户部署时使用
+DEFAULT_TENANT = "default"
+
 class WorkOrder(Base):
     """工单模型"""
     __tablename__ = "work_orders"
 
     id = Column(Integer, primary_key=True)
+    tenant_id = Column(String(50), nullable=False, default=DEFAULT_TENANT, index=True)
     order_id = Column(String(50), unique=True, nullable=False)
     title = Column(String(200), nullable=False)
     description = Column(Text, nullable=False)
@@ -63,6 +67,7 @@ class ChatSession(Base):
     __tablename__ = "chat_sessions"
 
     id = Column(Integer, primary_key=True)
+    tenant_id = Column(String(50), nullable=False, default=DEFAULT_TENANT, index=True)
     session_id = Column(String(100), unique=True, nullable=False)  # 唯一会话标识
     user_id = Column(String(100), nullable=True)  # 用户标识
     work_order_id = Column(Integer, ForeignKey("work_orders.id"), nullable=True)
@@ -100,6 +105,7 @@ class Conversation(Base):
     __tablename__ = "conversations"
 
     id = Column(Integer, primary_key=True)
+    tenant_id = Column(String(50), nullable=False, default=DEFAULT_TENANT, index=True)
     session_id = Column(String(100), ForeignKey("chat_sessions.session_id"), nullable=True)  # 关联会话
     work_order_id = Column(Integer, ForeignKey("work_orders.id"))
     user_message = Column(Text, nullable=False)
@@ -124,6 +130,7 @@ class KnowledgeEntry(Base):
     __tablename__ = "knowledge_entries"
 
     id = Column(Integer, primary_key=True)
+    tenant_id = Column(String(50), nullable=False, default=DEFAULT_TENANT, index=True)
     question = Column(Text, nullable=False)
     answer = Column(Text, nullable=False)
     category = Column(String(100), nullable=False)
@@ -164,6 +171,7 @@ class Analytics(Base):
     __tablename__ = "analytics"
 
     id = Column(Integer, primary_key=True)
+    tenant_id = Column(String(50), nullable=False, default=DEFAULT_TENANT, index=True)
     date = Column(DateTime, nullable=False)
     total_orders = Column(Integer, default=0)
     resolved_orders = Column(Integer, default=0)
@@ -184,6 +192,7 @@ class Alert(Base):
     __tablename__ = "alerts"
 
     id = Column(Integer, primary_key=True)
+    tenant_id = Column(String(50), nullable=False, default=DEFAULT_TENANT, index=True)
     rule_name = Column(String(100), nullable=False)
     alert_type = Column(String(50), nullable=False)
     level = Column(String(20), nullable=False)  # info, warning, error, critical
@@ -242,6 +251,7 @@ class User(Base):
     __tablename__ = "users"
 
     id = Column(Integer, primary_key=True)
+    tenant_id = Column(String(50), nullable=False, default=DEFAULT_TENANT, index=True)
     username = Column(String(50), unique=True, nullable=False)
     password_hash = Column(String(128), nullable=False)
     email = Column(String(120), unique=True, nullable=True)