refactor: 统一 Packet 通信协议 + 后端配置管理 + UI 清理

- 合并 server.py 到 core/__init__.py，使用统一 Packet 协议
- 后端管理配置持久化 (~/.trulymem/config.json)
- 前端移除 ConfigService，通过 BackendClient 与后端通信
- 删除 UI 中冗余的 AI 推理逻辑 (chat_service, tool_service, message_handler)
- 删除 core/tools 重复文件 (tool_executor, tool_limiter)
- 提示词管理器支持用户自定义 (~/.trulyemem/system_prompt.md)
- 启动入口优化配置路径逻辑
- 更新测试覆盖 (42 tests)
- 更新文档

ui/handlers/message_handler.py

@@ -1,98 +0,0 @@
-"""消息处理器"""
-
-from datetime import datetime
-from typing import TYPE_CHECKING
-from ..models.message import Message, ToolCall, ToolResult
-
-if TYPE_CHECKING:
-    from ..services.chat_service import ChatService
-    from ..widgets.message_history import MessageHistory
-    from ..widgets.operation_log import OperationLog
-
-
-class MessageHandler:
-    """消息处理器"""
-
-    def __init__(
-        self,
-        chat_service: "ChatService",
-        message_history: "MessageHistory",
-        operation_log: "OperationLog"
-    ):
-        self._chat_service = chat_service
-        self._message_history = message_history
-        self._operation_log = operation_log
-
-    async def handle_user_message(self, content: str) -> None:
-        """处理用户消息"""
-        # 创建用户消息
-        user_message = Message(
-            role="user",
-            content=content,
-            timestamp=datetime.now()
-        )
-
-        # 添加到历史
-        self._message_history.add_message(user_message)
-
-        # 发送到聊天服务
-        await self._process_response(content)
-
-    async def _process_response(self, user_input: str) -> None:
-        """处理响应"""
-        streaming_message = None
-        
-        async for event in self._chat_service.send_message(user_input):
-            if event["type"] == "user_message":
-                # 用户消息已处理
-                pass
-
-            elif event["type"] == "content_delta":
-                # 流式内容更新
-                if streaming_message is None:
-                    # 创建流式消息
-                    streaming_message = Message(
-                        role="assistant",
-                        content="",
-                        timestamp=datetime.now()
-                    )
-                    self._message_history.add_message(streaming_message)
-                
-                # 更新消息内容
-                self._message_history.update_latest_message(event["content"])
-
-            elif event["type"] == "assistant_message":
-                # 模型消息完成
-                if streaming_message:
-                    # 更新最终消息（包含工具调用信息）
-                    streaming_message.content = event["content"]
-                    streaming_message.tool_calls = event.get("tool_calls")
-                    streaming_message.tool_results = event.get("tool_results")
-                else:
-                    # 如果没有流式消息，直接添加
-                    message = Message(
-                        role="assistant",
-                        content=event["content"],
-                        timestamp=datetime.now(),
-                        tool_calls=event.get("tool_calls"),
-                        tool_results=event.get("tool_results")
-                    )
-                    self._message_history.add_message(message)
-
-            elif event["type"] == "tool_call":
-                # 工具调用开始
-                pass
-
-            elif event["type"] == "tool_result":
-                # 工具执行结果
-                log_entry = event["log_entry"]
-                self._operation_log.add_log(log_entry)
-
-            elif event["type"] == "error":
-                # 错误处理
-                error_message = Message(
-                    role="assistant",
-                    content=f"错误: {event['error']}",
-                    timestamp=datetime.now()
-                )
-                self._message_history.add_message(error_message)