feat(workspace): add workbench layout and traffic totals

Rework the default /workspace layout into a three-column view
with a left-side Workbench, centered terminal, and right-side
status monitor.

Add a new Workbench pane that groups file manager, command
history, and editor into tabs while preserving panel state.
Extend server status data to expose cumulative network upload
and download totals since boot, and show them in the monitor.

Include a lightweight migration for the old default layout and
update related locale strings, pane metadata, and knowledge
base records.

packages/frontend/src/components/LayoutRenderer.vue

@@ -88,6 +88,7 @@ const componentMap: Record<PaneName, Component> = {
   commandBar: defineAsyncComponent(() => import('./CommandInputBar.vue')),
   fileManager: defineAsyncComponent(() => import('./FileManager.vue')),
   editor: defineAsyncComponent(() => import('./FileEditorContainer.vue')),
+  workbench: defineAsyncComponent(() => import('./WorkspaceWorkbench.vue')),
   statusMonitor: defineAsyncComponent(() => import('./StatusMonitor.vue')),
   commandHistory: defineAsyncComponent(() => import('../views/CommandHistoryView.vue')),
   quickCommands: defineAsyncComponent(() => import('../views/QuickCommandsView.vue')),
@@ -131,6 +132,7 @@ const paneLabels = computed(() => ({
   commandBar: t('layout.pane.commandBar', '命令栏'),
   fileManager: t('layout.pane.fileManager', '文件管理器'),
   editor: t('layout.pane.editor', '编辑器'),
+  workbench: t('layout.pane.workbench', '工作台'),
   statusMonitor: t('layout.pane.statusMonitor', '状态监视器'),
   commandHistory: t('layout.pane.commandHistory', '命令历史'),
   quickCommands: t('layout.pane.quickCommands', '快捷指令'),
@@ -186,6 +188,21 @@ const componentProps = computed(() => {
         class: 'pane-content',
         // --- 移除事件转发 ---
       };
+    case 'workbench':
+      return {
+        tabs: props.editorTabs,
+        activeTabId: props.activeEditorTabId,
+        sessionId: currentActiveSession?.sessionId ?? props.activeSessionId,
+        instanceId: props.layoutNode.id || `workbench-main-${props.activeSessionId ?? 'unknown'}`,
+        dbConnectionId: currentActiveSession?.connectionId ?? null,
+        wsDeps: currentActiveSession ? {
+          sendMessage: currentActiveSession.wsManager.sendMessage,
+          onMessage: currentActiveSession.wsManager.onMessage,
+          isConnected: currentActiveSession.wsManager.isConnected,
+          isSftpReady: currentActiveSession.wsManager.isSftpReady
+        } : null,
+        class: 'flex flex-col flex-grow h-full overflow-hidden',
+      };
     case 'commandBar':
        return {
          class: 'pane-content',
@@ -240,6 +257,21 @@ const sidebarProps = computed(() => (paneName: PaneName | null, side: 'left' | '
        ...baseProps,
        // --- 移除事件转发 ---
      };
+   case 'workbench':
+     return {
+       ...baseProps,
+       tabs: editorTabsFromStore.value,
+       activeTabId: activeEditorTabIdFromStore.value,
+       sessionId: activeSession.value?.sessionId ?? props.activeSessionId,
+       instanceId: side === 'left' ? 'workbench-sidebar-left' : 'workbench-sidebar-right',
+       dbConnectionId: activeSession.value?.connectionId ?? null,
+       wsDeps: activeSession.value ? {
+         sendMessage: activeSession.value.wsManager.sendMessage,
+         onMessage: activeSession.value.wsManager.onMessage,
+         isConnected: activeSession.value.wsManager.isConnected,
+         isSftpReady: activeSession.value.wsManager.isSftpReady
+       } : null,
+     };
    case 'fileManager':
      // Only provide props if there's an active session
      if (activeSession.value) {
@@ -357,6 +389,7 @@ const getIconClasses = (paneName: PaneName): string[] => {
     case 'quickCommands': return ['fas', 'fa-bolt'];
     case 'dockerManager': return ['fab', 'fa-docker']; // Use 'fab' for Docker
     case 'editor': return ['fas', 'fa-file-alt'];
+    case 'workbench': return ['fas', 'fa-table-columns'];
     case 'statusMonitor': return ['fas', 'fa-tachometer-alt'];
     case 'suspendedSshSessions': return ['fas', 'fa-pause-circle']; // 图标：暂停圈
     // Add other specific icons here if needed