feat: add /manual command + fix cross-engine command routing

- /manual → switch to manual engine (CLI + TUI)
- /manual status → run manual engine sub-commands
- /manual restart → restart manual terminal
- /engine.manual status → now works from any engine (not just manual)
- Fixed handle_engine_command to route to correct engine by name

xcli_core/tui.py

@@ -719,6 +719,7 @@ if TEXTUAL_AVAILABLE:
                 'tools': lambda: self._show_tools(),
                 'engines': lambda: self._show_engines(),
                 'tui': lambda: self._system("已在 TUI 模式中"),
+                'manual': lambda: self._handle_manual(args),
             }
 
             handler = cmds.get(name)
@@ -753,6 +754,24 @@ if TEXTUAL_AVAILABLE:
   Enter      换行        Tab        缩进"""
             self._system(help_text)
 
+        def _handle_manual(self, args):
+            """处理 /manual 命令"""
+            if 'manual' not in self.cli.engines:
+                self._error("manual 引擎未加载")
+                return
+            if not args:
+                # 切换到 manual 引擎
+                if self.bridge.switch_engine('manual'):
+                    self._system("已切换到 manual 引擎")
+                    self._update_sidebar()
+                else:
+                    self._error("切换失败")
+            else:
+                # 执行 manual 引擎子命令
+                result = self.cli.engines['manual'].handle_command(args)
+                if result:
+                    self._system(result)
+
         def _switch_cli(self):
             self._system("切换到命令行模式...")
             self.cli.tui_output_callback = None