修复: webview尺寸收窄卡住与兜底失效闪退

- 窗口尺寸变化后webview收窄卡住根修
- 尺寸兜底失效致闪退与修复空转加固
- 跨服务器预览残留清理

frontend/src/components/FileSystem/index.vue

@@ -513,8 +513,11 @@ const fileEditorPanelConfig = computed(() => {
     currentFileExtension,
     isBinaryFile: isBinaryFileRef.value,
     fileMtime: selectedFileItem.value?.modified_time || '',
-    // 多 tab
-    previewTabs: multiPreview.tabs.value,
+    // 多 tab（按当前服务器过滤，跨服务器的标签不显示在浮动标签栏）
+    previewTabs: (() => {
+      const pid = connectionManager.activeProfile?.id
+      return multiPreview.tabs.value.filter(t => (t.profileId ?? 'local-default') === pid)
+    })(),
     activeTabId: multiPreview.activeTabId.value,
     // 预览插件(优先于内置 v-if 链;.drawio/.dio 命中,其余为 null)
     activePlugin: currentFileName ? resolvePreviewHandler(currentFileName) : null,
@@ -569,6 +572,7 @@ const handleFileChanged = async (event: any) => {
 // 同路径也强制重载：navigate 同路径早退时列表会永远不加载
 const switchConnection = async (profileId: string) => {
   await connectionManager.connect(profileId)
+  await syncPreviewToActiveProfile()
   await loadCommonPaths()
   const targetPath = connectionManager.isRemote() ? '/' : 'C:/'
   if (filePath.value === targetPath) {
@@ -596,6 +600,7 @@ const handleGoToPath = async (path: string) => {
   const targetProfileId = getProfileIdForPath(path)
   if (targetProfileId && targetProfileId !== connectionManager.activeProfile?.id) {
     await connectionManager.connect(targetProfileId)
+    await syncPreviewToActiveProfile()
   }
   await navigate(path)
 }
@@ -1459,6 +1464,26 @@ const doCloseTab = (tabId: string) => {
   }
 }
 
+/** 切换服务器后预览区联动：只显示当前服务器的标签与内容，避免旧服务器文档残留卡住 */
+const syncPreviewToActiveProfile = async () => {
+  const currentProfileId = connectionManager.activeProfile?.id
+  const isMine = (t: PreviewTab) => (t.profileId ?? 'local-default') === currentProfileId
+
+  const active = multiPreview.activeTab.value
+  if (active && isMine(active)) return
+
+  // 面板上残留的是旧服务器内容，先缓存回它自己的 tab（loaded 标记让切回时秒恢复）
+  cacheCurrentTabState()
+  const mine = multiPreview.tabs.value.find(isMine)
+  if (mine) {
+    await activateTab(mine)
+  } else {
+    // 当前服务器没有已打开的预览：回到空白预览态
+    selectedFileItem.value = null
+    clearContent()
+  }
+}
+
 /** 缓存当前 tab 的编辑状态 */
 const cacheCurrentTabState = () => {
   multiPreview.cacheCurrentTab({