feat: 完善词典子图，添加API调用和前端格式化工具

- 完善词典子图：添加生词本功能
- 创建API调用工具：dictionary_api
- 添加前端格式化展示工具：result_formatter.py
- 创建通讯录和资讯子图的基本结构
- 更新主图状态结构，添加MainGraphState
- 添加subgraph_builder.py用于子图集成

backend/app/agent_subgraphs/contact/nodes.py

@@ -0,0 +1,217 @@
+"""
+通讯录子图节点
+Contact Subgraph Nodes
+"""
+
+from typing import Dict, Any
+from datetime import datetime
+
+from .state import ContactState, ContactAction, Contact, Email
+
+
+def parse_intent(state: ContactState) -> ContactState:
+    """
+    解析用户意图节点
+    确定用户想做什么操作
+    """
+    state.current_phase = "intent_parsing"
+    
+    query_lower = state.user_query.lower()
+    
+    # 简单的关键词匹配（真实场景应该用LLM）
+    if any(keyword in query_lower for keyword in ["联系人", "contact", "list"]):
+        state.action = ContactAction.CONTACT_LIST
+        state.action_params = {"query": state.user_query}
+    
+    elif any(keyword in query_lower for keyword in ["添加", "add", "新建", "save"]):
+        state.action = ContactAction.CONTACT_ADD
+        # TODO: 提取联系人信息
+    
+    elif any(keyword in query_lower for keyword in ["邮件", "email", "inbox"]):
+        state.action = ContactAction.EMAIL_LIST
+    
+    elif any(keyword in query_lower for keyword in ["发送邮件", "send email", "发邮件"]):
+        state.action = ContactAction.EMAIL_SEND
+    
+    else:
+        state.action = ContactAction.SNIFF_CONTACTS
+    
+    return state
+
+
+def list_contacts(state: ContactState) -> ContactState:
+    """
+    列出联系人节点
+    """
+    state.current_phase = "listing_contacts"
+    
+    # TODO: 从数据库查询
+    # 暂时返回空列表
+    state.contacts = []
+    state.success = True
+    state.final_result = "暂无联系人"
+    
+    return state
+
+
+def add_contact(state: ContactState) -> ContactState:
+    """
+    添加联系人节点
+    """
+    state.current_phase = "adding_contact"
+    
+    # TODO: 实现添加联系人逻辑
+    state.success = True
+    state.final_result = "联系人添加成功（待实现）"
+    
+    return state
+
+
+def list_emails(state: ContactState) -> ContactState:
+    """
+    列出邮件节点
+    """
+    state.current_phase = "listing_emails"
+    
+    # TODO: 从IMAP查询
+    state.emails = []
+    state.success = True
+    state.final_result = "暂无邮件"
+    
+    return state
+
+
+def generate_email_draft(state: ContactState) -> ContactState:
+    """
+    生成邮件草稿节点
+    """
+    state.current_phase = "generating_draft"
+    
+    # TODO: 使用LLM生成邮件草稿
+    state.draft_subject = "邮件主题"
+    state.draft_recipient = "recipient@example.com"
+    state.draft_body = "这是邮件内容..."
+    
+    # 进入人工审核状态
+    state.pending_review = True
+    state.review_type = "email_send"
+    state.review_prompt = "请确认是否发送此邮件"
+    
+    return state
+
+
+def human_review(state: ContactState) -> ContactState:
+    """
+    人工审核节点
+    这里会让用户确认/修改
+    """
+    state.current_phase = "reviewing"
+    
+    # 注意：真实的LangGraph会在这里使用interrupt()暂停
+    # 这里我们只设置状态，让外层处理
+    if state.review_approved is True:
+        state.pending_review = False
+    elif state.review_approved is False:
+        state.pending_review = False
+        state.error_message = "发送已取消"
+        state.success = False
+    
+    return state
+
+
+def send_email(state: ContactState) -> ContactState:
+    """
+    发送邮件节点
+    """
+    state.current_phase = "sending_email"
+    
+    # TODO: 使用SMTP发送邮件
+    state.success = True
+    state.final_result = "邮件发送成功（待实现）"
+    
+    return state
+
+
+def sniff_contacts(state: ContactState) -> ContactState:
+    """
+    智能嗅探节点
+    从对话中提取可能的联系人信息
+    """
+    state.current_phase = "sniffing"
+    
+    # TODO: 实现智能嗅探
+    state.success = True
+    state.final_result = "智能嗅探完成（待实现）"
+    
+    return state
+
+
+def format_result(state: ContactState) -> ContactState:
+    """
+    格式化结果节点
+    """
+    state.current_phase = "formatting"
+    
+    # 根据不同action生成不同的格式化输出
+    if state.action == ContactAction.CONTACT_LIST:
+        if state.contacts:
+            result = "联系人列表：\n"
+            for i, contact in enumerate(state.contacts, 1):
+                result += f"{i}. {contact.name}"
+                if contact.phone:
+                    result += f" - {contact.phone}"
+                if contact.email:
+                    result += f" ({contact.email})"
+                result += "\n"
+        else:
+            result = "暂无联系人"
+        state.final_result = result
+    
+    elif state.action == ContactAction.EMAIL_LIST:
+        if state.emails:
+            result = "邮件列表：\n"
+            for i, email in enumerate(state.emails[:10], 1):
+                result += f"{i}. {email.subject} - {email.sender}\n"
+        else:
+            result = "暂无邮件"
+        state.final_result = result
+    
+    else:
+        if not state.final_result:
+            state.final_result = "操作完成"
+    
+    state.current_phase = "done"
+    return state
+
+
+def should_continue(state: ContactState) -> str:
+    """
+    条件路由：决定下一步该做什么
+    """
+    if state.error_message:
+        return "finalize"
+    
+    # 如果在审核中，等待
+    if state.pending_review:
+        return "human_review"
+    
+    # 根据action路由
+    if state.action == ContactAction.NONE:
+        return "parse_intent"
+    elif state.action == ContactAction.CONTACT_LIST:
+        return "list_contacts"
+    elif state.action == ContactAction.CONTACT_ADD:
+        return "add_contact"
+    elif state.action == ContactAction.EMAIL_LIST:
+        return "list_emails"
+    elif state.action == ContactAction.EMAIL_SEND:
+        if state.pending_review:
+            return "human_review"
+        elif state.draft_subject:
+            return "send_email"
+        else:
+            return "generate_email_draft"
+    elif state.action == ContactAction.SNIFF_CONTACTS:
+        return "sniff_contacts"
+    else:
+        return "format_result"