refactor: packet-based IPC with core/ui separation

- All logic in core layer (BackendServer runs independently)
- Packet protocol: {id, type, body} for all communications
- UI simplified: just input→backend→display
- Config, history, tools all handled by core
- BackendServer can run standalone without UI

ui/app.py

@@ -2,17 +2,12 @@ import asyncio
 from pathlib import Path
 from textual.app import App, ComposeResult
 from textual.binding import Binding
-from datetime import datetime
 
 from core import BackendServer, BackendClient
-from .models.message import Message, ToolCall, ToolResult
-from .models.config import AppConfig
-from .models.log_entry import LogEntry
-from .services.config_manager import ConfigManager
-from core import BackendClient
+from .models.message import Message
 
 
-class GraphMemoryApp(App[None]):
+class GraphMemoryApp(App):
     CSS_PATH = [
         Path(__file__).parent / "styles" / "app.css",
         Path(__file__).parent / "styles" / "messages.css",
@@ -23,257 +18,108 @@ class GraphMemoryApp(App[None]):
         Binding("f1", "show_help", "帮助"),
         Binding("f2", "toggle_sidebar", "侧边栏"),
         Binding("f3", "toggle_tool_details", "工具详情"),
-        Binding("f4", "focus_query", "查询"),
         Binding("f5", "clear_history", "清屏"),
         Binding("f6", "quit", "退出"),
     ]
 
-    def __init__(self, config: AppConfig | None = None, backend_server: BackendServer | None = None, **kwargs):
+    def __init__(self, backend_server: BackendServer = None, **kwargs):
         super().__init__(**kwargs)
-        self._config_manager = ConfigManager()
-        
-        if config:
-            self._config = config
-        elif self._config_manager.exists():
-            self._config = self._config_manager.load()
-        else:
-            self._config = AppConfig.from_env()
-        
-        if backend_server:
-            self._backend_server = backend_server
-            self._backend_client = BackendClient(backend_server)
-        else:
-            self._backend_server: BackendServer | None = None
-            self._backend_client: BackendClient | None = None
+        self._backend_server = backend_server
+        self._backend_client = BackendClient(backend_server) if backend_server else None
 
     def compose(self) -> ComposeResult:
         from .widgets.left_panel import LeftPanel
         from .widgets.right_panel import RightPanel
         from .widgets.status_bar import StatusBar
-        
         yield LeftPanel()
-        yield RightPanel(self._config, use_embedded_db=True)
+        yield RightPanel()
         yield StatusBar()
 
     def on_mount(self) -> None:
+        if not self._backend_server:
+            from .widgets.message_history import MessageHistory
+            history = self.query_one(MessageHistory)
+            error = Message(role="assistant", content="后端未初始化")
+            history.add_message(error)
+            return
+        
+        status = self._backend_client.get_status()
+        api_configured = status.get("config", {}).get("api_key", "") != ""
+        
         from .widgets.message_history import MessageHistory
         history = self.query_one(MessageHistory)
-
-        try:
-            self._backend_server = BackendServer(
-                db_path="graph_memory.db",
-                use_embedded_db=True
-            )
-            self._backend_server.start(
-                api_key=self._config.api_key,
-                base_url=self._config.base_url
-            )
-            
-            self._backend_client = BackendClient(self._backend_server)
-
-            welcome = Message(
-                role="assistant",
-                content="系统初始化成功！\n\n"
-                       f"数据库: 内嵌SQLite (graph_memory.db)\n"
-                       f"API Key: {'已配置' if self._config.api_key else '未配置'}\n\n"
-                       "现在可以开始对话了！",
-            )
-            history.add_message(welcome)
-
-        except Exception as e:
-            error = Message(
-                role="assistant",
-                content=f"初始化失败: {str(e)}\n\n"
-                       "请检查：\n"
-                       "1. API Key 是否配置\n"
-                       "2. 网络连接是否正常\n\n"
-                       "按F2打开侧边栏配置API Key",
-            )
-            history.add_message(error)
+        welcome = Message(
+            role="assistant",
+            content=f"系统就绪\nAPI Key: {'已配置' if api_configured else '未配置'}\n\n输入消息开始对话"
+        )
+        history.add_message(welcome)
 
     def on_unmount(self) -> None:
-        if self._backend_server:
-            self._backend_server.shutdown()
+        if self._backend_client:
+            self._backend_client.shutdown()
 
     def action_show_help(self) -> None:
-        help_text = """
-快捷键：
-F1 - 帮助
-F2 - 切换侧边栏
-F3 - 工具详情
-F4 - 查询框
-F5 - 清屏
-F6 - 退出
-
-输入消<EFBFBD><EFBFBD>后按 Enter 发送
-        """
-        self.notify(help_text, title="帮助", timeout=10)
+        self.notify("F1-帮助 F2-侧边栏 F3-工具详情 F5-清屏 F6-退出", title="快捷键", timeout=10)
 
     def action_toggle_sidebar(self) -> None:
         from .widgets.right_panel import RightPanel
         sidebar = self.query_one(RightPanel)
         sidebar.toggle()
-        sidebar.update_title()
 
     def action_toggle_tool_details(self) -> None:
         from .widgets.message_history import MessageHistory
         history = self.query_one(MessageHistory)
         history.toggle_latest_tool_details()
 
-    def action_focus_query(self) -> None:
-        from .widgets.right_panel import RightPanel
-        sidebar = self.query_one(RightPanel)
-        
-        if not sidebar.has_cypher_query_box():
-            self.notify("查询框仅在 Neo4j 模式下可用", title="提示", timeout=3)
-            return
-        
-        if sidebar.is_collapsed():
-            sidebar.toggle()
-            sidebar.update_title()
-        
-        query_box = sidebar.get_cypher_query_box()
-        if query_box:
-            query_box.focus()
-
     def action_clear_history(self) -> None:
         from .widgets.message_history import MessageHistory
         history = self.query_one(MessageHistory)
         history.clear_messages()
 
     def on_input_box_send_message(self, event) -> None:
-        from .widgets.input_box import InputBox
-        from .widgets.message_history import MessageHistory
-        from .widgets.right_panel import RightPanel
+        if not self._backend_client:
+            return
         
-        try:
-            history = self.query_one(MessageHistory)
-            user_message = Message(role="user", content=event.content)
-            history.add_message(user_message)
-
-            if not self._config.api_key:
-                response_msg = Message(
-                    role="assistant",
-                    content="请先配置API Key。\n\n按F2打开侧边栏，输入API Key后按Enter保存。",
-                )
-                history.add_message(response_msg)
-                return
-
-            processing_msg = Message(role="assistant", content="正在处理...")
-            history.add_message(processing_msg)
-
-            asyncio.create_task(self._process_message_async(event.content))
-
-        except Exception as e:
-            error_msg = Message(role="assistant", content=f"错误: {str(e)}")
-            history.add_message(error_msg)
-
-    async def _process_message_async(self, user_input: str) -> None:
+        user_input = event.content
         from .widgets.message_history import MessageHistory
-        from .widgets.right_panel import RightPanel
-        
         history = self.query_one(MessageHistory)
-        log = self.query_one(RightPanel).get_operation_log()
+        
+        history.add_message(Message(role="user", content=user_input))
+        history.add_message(Message(role="assistant", content="处理中..."))
+        
+        asyncio.create_task(self._process(user_input))
 
+    async def _process(self, user_input: str) -> None:
         try:
-            if not self._backend_client:
-                raise Exception("后端未初始化")
-
             result = await asyncio.get_event_loop().run_in_executor(
                 None,
-                lambda: self._backend_client.process_message(user_input)
+                lambda: self._backend_client.send_message(user_input)
             )
-
-            content = result.get("content", "(无回复)")
-            tool_calls_data = result.get("tool_calls", [])
-            rejected_tools = result.get("rejected_tools", [])
-
-            tool_calls = []
-            tool_results = []
             
-            for tc in tool_calls_data:
-                tc_obj = ToolCall(
-                    id=tc.get("id", ""),
-                    name=tc.get("name", ""),
-                    arguments=tc.get("arguments", {})
-                )
-                tool_calls.append(tc_obj)
-                
-                tr = ToolResult(
-                    tool_call_id=tc_obj.id,
-                    name=tc_obj.name,
-                    arguments=tc_obj.arguments,
-                    result=tc.get("result", ""),
-                    success=not tc.get("result", "").startswith("工具执行<EFBFBD><EFBFBD><EFBFBD>误")
-                )
-                tool_results.append(tr)
-                
-                log_entry = LogEntry(
-                    tool_name=tc_obj.name,
-                    arguments=tc_obj.arguments,
-                    result=tc.get("result", ""),
-                )
-                log.add_log(log_entry)
-
-            assistant_message = Message(
-                role="assistant",
-                content=content,
-                tool_calls=tool_calls if tool_calls else None,
-                tool_results=tool_results if tool_results else None
-            )
-
-            history.add_message(assistant_message)
-            self.refresh()
-
-        except Exception as e:
-            error_msg = str(e)
+            from .widgets.message_history import MessageHistory
+            history = self.query_one(MessageHistory)
+            history.clear_messages()
             
-            if "Connection error" in error_msg or "connection" in error_msg.lower():
-                help_text = """
-网络连接错误！可能的原因：
-1. API Key 未配置或无效
-2. 网络无法访问 API 服务器
-3. API 服务器暂时不可用
-
-解决方法：
-按 F2 展开侧边栏，检查并配置 API Key
-检查网络连接
-"""
-            elif "API Key" in error_msg:
-                help_text = """
-API Key 未配置！
-
-请按以下步骤配置：
-1. 按 F2 展开右侧边栏
-2. 点击"配置"展开配置区
-3. 在 API Key 输入框输入你的密钥
-4. 按 Enter 键保存配置
-
-获取 API Key: https://platform.deepseek.com/
-"""
+            history.add_message(Message(role="user", content=user_input))
+            
+            if result.get("success"):
+                content = result.get("content", "(无回复)")
+                history.add_message(Message(role="assistant", content=content))
             else:
-                help_text = f"\n详细错误: {error_msg}"
-            
-            error_message = Message(role="assistant", content=f"错误: {error_msg}\n{help_text}")
-            history.add_message(error_message)
+                error = result.get("error", "未知错误")
+                history.add_message(Message(role="assistant", content=f"错误: {error}"))
+                
+        except Exception as e:
+            from .widgets.message_history import MessageHistory
+            history = self.query_one(MessageHistory)
+            history.add_message(Message(role="assistant", content=f"错误: {str(e)}"))
 
-    def on_config_section_config_changed(self, event) -> None:
-        from .widgets.right_panel import RightPanel
+    def on_config_changed(self, event) -> None:
+        if not self._backend_client:
+            return
         
-        self._config = event.config
-        self._config_manager.save(self._config)
+        api_key = event.api_key
+        base_url = event.base_url
         
-        try:
-            right_panel = self.query_one(RightPanel)
-            right_panel._config = self._config
-        except Exception:
-            pass
-        
-        if self._backend_client:
-            self._backend_client.update_config(
-                api_key=self._config.api_key,
-                base_url=self._config.base_url
-            )
-            self.notify("配置已保存并应用", title="配置")
-        else:
-            self.notify("配置已保存，但后端未初始化", title="警告")
+        result = self._backend_client.update_config(api_key=api_key, base_url=base_url)
+        self.notify("配置已保存" if result.get("success") else "配置失败", title="配置")