chore(bundle): NSIS 安装器切换为简体中文界面

弹窗（.modal 带 overflow-y:auto）里的下拉展开层是 absolute 定位，
会被弹窗滚动盒裁掉下半截（Git 同步设置里实测被遮挡）。展开层改经
Portal 挂到 body、按触发钮 rect 用 fixed 定位：下方空间不足时
向上翻，maxHeight 按可用空间夹取；窗口 resize 时关闭。
useDismiss 泛化为可传多个 ref（触发器与 Portal 菜单两棵子树都算内）。
CSS 相应去掉 .dropdown-menu 的 absolute 定位（几何改由内联给出）。
验证：vitest 124+2（新增翻转几何断言：贴底触发钮翻上展开、
Portal 落点不在组件容器内）；无头 Chromium 实测弹窗内下拉菜单
完整落在视口内、8 项全显、已逃出弹窗 DOM。

.gitignore

@@ -4,3 +4,5 @@ target/
 src-tauri/target/
 src-tauri/gen/
 *.tsbuildinfo
+.idea/
+vite.config.ts.timestamp-*

docs/29-全项目审计.md

@@ -132,6 +132,13 @@ src-tauri/src/ 全部（1289 行）。先说结论：发现 **1 个高危数据
 - D1（中）非 UTF-8 文件首次保存被静默转码为 UTF-8（GBK/UTF-16
   文档存一次即变 UTF-8）：编辑器内部统一 UTF-8 是既定设计，但
   落盘编码变更应至少首次提示一次。需前端交互拍板，未擅自加。
+  → **已于当晚按用户拍板实现**：saveTab 在落盘前拦截，首次保存
+  弹 EncodingConvertModal 说明将转 UTF-8（按路径记已确认、本次
+  运行只提示一次）；自动保存不弹窗也不静默转码，跳过该文档等
+  手动保存时提示；确认后以冻结快照完成落盘，标签 encoding 如实
+  更新为 UTF-8。弹窗渲染置于所有弹窗之后（避免被关窗确认框
+  盖住）。vitest 123+2（含弹窗契约测试）。真机验证点：拿一个
+  GBK 文档改字后 Ctrl+S，应先弹提示、确认后才落盘。
 - D2（中）专注模式跨块时全量重建装饰集：大文档每次回车重建与
   顶层块数等量的装饰对象。改增量方案需重构插件，单独立项。
 - D3（低）源码模式每次击键物化全文回写 App（无渲染模式的 200ms
@@ -183,3 +190,11 @@ src-tauri/src/ 全部（1289 行）。先说结论：发现 **1 个高危数据
 - H1 的守卫交错无法在 jsdom 自动化复现（见上），真机侧可用
   「打开 >60K 文档后立刻连开多个标签挤掉其窗格，再回看该文档
   是否完整」一验。
+- **勘误（2026-11-14 晚，Windows 构建回报）**：本轮 M1 与 docs/27
+  的 Git 命令共 6 处用了 `tokio::task::spawn_blocking`，但工程并
+  没有 tokio 直接依赖（Cargo.toml 只有 tauri 等 7 个），Windows
+  构建报 E0433。已全部改为工程既有写法的
+  `tauri::async_runtime::spawn_blocking`（read/write 命令一直在
+  用），并全量核对源码中所有外部 crate 前缀与 Cargo.toml 依赖
+  一致、无其他幻影 crate。教训：写 Rust 时新引入的 crate 路径
+  必须先对 Cargo.toml 存量，沙箱无法完整编译时尤其如此。

src-tauri/src/commands.rs

@@ -258,7 +258,7 @@ fn write_new_file(dir: &Path, file_name: &str, data: &[u8]) -> Result<PathBuf, S
 /// 大文件会冻 UI 线程且内存整载（docs/29）。
 #[tauri::command]
 pub async fn copy_to_assets(source: String, doc_path: String) -> Result<String, String> {
-    tokio::task::spawn_blocking(move || {
+    tauri::async_runtime::spawn_blocking(move || {
         let src = PathBuf::from(&source);
         let name = sanitize_file_name(
             &src.file_name()
@@ -287,7 +287,7 @@ pub async fn save_bytes_to_assets(
     file_name: String,
     base64: String,
 ) -> Result<String, String> {
-    tokio::task::spawn_blocking(move || {
+    tauri::async_runtime::spawn_blocking(move || {
         let name = sanitize_file_name(&file_name);
         let bytes = base64_decode(&base64)?;
         if bytes.len() as u64 > MAX_ASSET_BYTES {
@@ -784,7 +784,7 @@ fn git_status_inner(root: &str) -> GitStatusInfo {
 
 #[tauri::command]
 pub async fn git_status(root: String) -> GitStatusInfo {
-    tokio::task::spawn_blocking(move || git_status_inner(&root))
+    tauri::async_runtime::spawn_blocking(move || git_status_inner(&root))
         .await
         .unwrap_or(GitStatusInfo {
             is_repo: false,
@@ -799,7 +799,7 @@ pub async fn git_status(root: String) -> GitStatusInfo {
 
 #[tauri::command]
 pub async fn git_init_repo(root: String, remote_url: String, branch: String) -> Result<GitStatusInfo, String> {
-    tokio::task::spawn_blocking(move || {
+    tauri::async_runtime::spawn_blocking(move || {
         let dir = Path::new(&root);
         let b = validate_branch(&branch)?;
         let url = validate_remote_url(&remote_url)?;
@@ -833,7 +833,7 @@ pub async fn git_init_repo(root: String, remote_url: String, branch: String) ->
 
 #[tauri::command]
 pub async fn git_set_remote(root: String, remote_url: String) -> Result<GitStatusInfo, String> {
-    tokio::task::spawn_blocking(move || {
+    tauri::async_runtime::spawn_blocking(move || {
         let dir = Path::new(&root);
         let url_owned = validate_remote_url(&remote_url)?;
         let url = url_owned.as_str();
@@ -855,7 +855,7 @@ pub async fn git_set_remote(root: String, remote_url: String) -> Result<GitStatu
 
 #[tauri::command]
 pub async fn git_sync_now(root: String, message: String) -> Result<GitSyncOutcome, String> {
-    tokio::task::spawn_blocking(move || {
+    tauri::async_runtime::spawn_blocking(move || {
         let dir = Path::new(&root);
         let st = git_status_inner(&root);
         if !st.is_repo {

src-tauri/tauri.conf.json

@@ -1 +1 @@
-{"$schema":"https://schema.tauri.app/config/2","app":{"security":{"csp":null},"windows":[{"center":true,"decorations":false,"height":820,"label":"main","minHeight":600,"minWidth":920,"resizable":true,"title":"new-markdown","width":1280,"dragDropEnabled":false}]},"build":{"beforeBuildCommand":"npm run build","beforeDevCommand":"npm run dev","devUrl":"http://localhost:1420","frontendDist":"../dist"},"bundle":{"active":true,"category":"Productivity","icon":["icons/32x32.png","icons/128x128.png","icons/128x128@2x.png","icons/icon.ico","icons/icon.png"],"shortDescription":"Windows Markdown 所见即所得编辑器","targets":["nsis","msi"]},"identifier":"app.newmarkdown.desktop","productName":"new-markdown","version":"0.1.0"}
+{"$schema":"https://schema.tauri.app/config/2","app":{"security":{"csp":null},"windows":[{"center":true,"decorations":false,"height":820,"label":"main","minHeight":600,"minWidth":920,"resizable":true,"title":"new-markdown","width":1280,"dragDropEnabled":false}]},"build":{"beforeBuildCommand":"npm run build","beforeDevCommand":"npm run dev","devUrl":"http://localhost:1420","frontendDist":"../dist"},"bundle":{"active":true,"category":"Productivity","windows":{"nsis":{"languages":["SimpChinese"],"displayLanguageSelector":false}},"icon":["icons/32x32.png","icons/128x128.png","icons/128x128@2x.png","icons/icon.ico","icons/icon.png"],"shortDescription":"Windows Markdown 所见即所得编辑器","targets":["nsis","msi"]},"identifier":"app.newmarkdown.desktop","productName":"new-markdown","version":"0.1.0"}

src/App.tsx

@@ -18,7 +18,7 @@ const SourceEditor = lazy(() => import('./components/SourceEditor'))
 import { offsetInMarkdown, type CursorAnchor } from './editor/cursorSync'
 import { insertPlainText, insertLinkText } from './editor/paste'
 import { isImeComposing } from './utils/ime'
-import { ConfirmSaveModal, AboutModal, ShortcutsModal, LinkModal, ErrorModal } from './components/Modals'
+import { ConfirmSaveModal, AboutModal, ShortcutsModal, LinkModal, ErrorModal , EncodingConvertModal } from './components/Modals'
 import { tabsReducer, createTab, activeTab, isDirty, type DocTab, type TabsState } from './stores/tabs'
 import { countWords, countChars, extractOutline, baseName, isPathInside, type OutlineItem } from './utils/text'
 import { callUndo, callRedo, focusEditor, type CursorInfo } from './editor/editor'
@@ -472,11 +472,32 @@ export default function App() {
 
   const handleSidebarOpenFolder = useCallback(() => { void openFolder() }, [openFolder])
 
-  const saveTab = useCallback(async (target: DocTab, saveAs: boolean): Promise<boolean> => {
+  // 非 UTF-8 文档保存转码提示（docs/29 D1，用户拍板加）：按路径记已确认，
+  // 本次运行内同一文件只提示一次；确认后走 finishSave 完成落盘收尾。
+  const encodingAckedRef = useRef<Set<string>>(new Set())
+  const [encodingPrompt, setEncodingPrompt] = useState<{ target: DocTab; path: string; snapshot: string } | null>(null)
+
+  /** 保存落盘后的收尾：标已保存（编码如实记为 UTF-8）、刷树、更新基线、清恢复记录。 */
+  const finishSave = useCallback(async (target: DocTab, path: string, snapshot: string) => {
+    const oldKey = recoveryKey(target)
+    dispatch({ type: 'saved', id: target.id, savedContent: snapshot, path, title: baseName(path), encoding: 'UTF-8' })
+    // 落点变化（未命名首次保存、另存为）意味着磁盘上多/改了一个文件，刷新左侧文件树
+    if (target.path !== path) setTreeRefresh((n) => n + 1)
+    const stat = await statFile(path)
+    if (stat.exists) baselinesRef.current.set(target.id, { mtimeMs: stat.mtimeMs, size: stat.size })
+    // 恢复记录可能按旧键（未命名/旧路径）写入，新旧键都清，避免下次启动误报草稿
+    const newKey = recoveryKey({ id: target.id, path })
+    for (const key of new Set([oldKey, newKey])) {
+      recoveryWrittenRef.current.delete(key)
+      void store.deleteRecovery(key)
+    }
+    pushRecent(path)
+  }, [pushRecent])
+
+  const saveTab = useCallback(async (target: DocTab, saveAs: boolean, fromAutosave = false): Promise<boolean> => {
     // 审计修复：保存用调用时刻的快照；saved 只把这份快照标为已保存，
     // 写盘期间新输入的内容保持「脏」，不会被误标、不会丢恢复记录。
     const snapshot = target.content
-    const oldKey = recoveryKey(target)
     try {
       if (!tauriMode) {
         downloadTextFile(`${target.title}.md`, snapshot)
@@ -498,25 +519,35 @@ export default function App() {
         path = await pickSaveFile(path ?? (workspaceRoot ? joinPath(workspaceRoot, `${target.title}.md`) : `${target.title}.md`))
         if (!path) return false
       }
-      await writeTextFile(path, toDiskContent(snapshot, target.lineEnding), target.hadBom)
-      dispatch({ type: 'saved', id: target.id, savedContent: snapshot, path, title: baseName(path) })
-      // 落点变化（未命名首次保存、另存为）意味着磁盘上多/改了一个文件，刷新左侧文件树
-      if (target.path !== path) setTreeRefresh((n) => n + 1)
-      const stat = await statFile(path)
-      if (stat.exists) baselinesRef.current.set(target.id, { mtimeMs: stat.mtimeMs, size: stat.size })
-      // 恢复记录可能按旧键（未命名/旧路径）写入，新旧键都清，避免下次启动误报草稿
-      const newKey = recoveryKey({ id: target.id, path })
-      for (const key of new Set([oldKey, newKey])) {
-        recoveryWrittenRef.current.delete(key)
-        void store.deleteRecovery(key)
+      // 非 UTF-8 文档保存会转码为 UTF-8：首次保存前提示一次（按路径记已确认）。
+      // 自动保存不弹窗、也不静默转码——跳过本轮，等手动保存/关窗保存时提示。
+      if (target.encoding !== 'UTF-8' && !encodingAckedRef.current.has(path)) {
+        if (fromAutosave) return false
+        setEncodingPrompt({ target, path, snapshot })
+        return false
       }
-      pushRecent(path)
+      await writeTextFile(path, toDiskContent(snapshot, target.lineEnding), target.hadBom)
+      await finishSave(target, path, snapshot)
       return true
     } catch (e) {
       setError(String(e))
       return false
     }
-  }, [tauriMode, pushRecent, workspaceRoot])
+  }, [tauriMode, finishSave, workspaceRoot])
+
+  /** 编码提示确认：记下该路径已确认，用弹窗时冻结的快照完成落盘。 */
+  const confirmEncodingSave = useCallback(async () => {
+    const job = encodingPrompt
+    if (!job) return
+    setEncodingPrompt(null)
+    encodingAckedRef.current.add(job.path)
+    try {
+      await writeTextFile(job.path, toDiskContent(job.snapshot, job.target.lineEnding), job.target.hadBom)
+      await finishSave(job.target, job.path, job.snapshot)
+    } catch (e) {
+      setError(String(e))
+    }
+  }, [encodingPrompt, finishSave])
 
   const requestClose = useCallback((ids: string[], after: () => void) => {
     const dirtyOnes = state.tabs.filter((t) => ids.includes(t.id) && isDirty(t))
@@ -731,7 +762,7 @@ export default function App() {
     const timer = window.setInterval(() => {
       for (const t of stateRef.current.tabs) {
         // 冲突弹窗正等用户裁决的标签不自动保存，否则会抢先覆盖外部修改
-        if (t.path && isDirty(t) && conflictRef.current !== t.id) void saveTabRef.current(t, false)
+        if (t.path && isDirty(t) && conflictRef.current !== t.id) void saveTabRef.current(t, false, true)
       }
     }, Math.max(10, ui.autosaveSeconds) * 1000)
     return () => window.clearInterval(timer)
@@ -1363,7 +1394,7 @@ export default function App() {
   }, [tauriMode, flash])
 
   anyModalRef.current = Boolean(
-    modal || appearanceOpen || exportOpen || pendingClose || conflict
+    modal || appearanceOpen || exportOpen || pendingClose || conflict || encodingPrompt
     || promptSpec || confirmSpec || quitOpen || gitSettingsOpen || (recoveryOffer.length > 0 && !recoveryDismissed),
   )
   findOpenRef.current = findUi.open
@@ -1857,6 +1888,15 @@ export default function App() {
         />
       )}
       {error && <ErrorModal message={error} onClose={() => setError(null)} />}
+      {encodingPrompt && (
+        <EncodingConvertModal
+          encoding={encodingPrompt.target.encoding}
+          fileName={baseName(encodingPrompt.path)}
+          onConfirm={() => { void confirmEncodingSave() }}
+          onCancel={() => setEncodingPrompt(null)}
+        />
+      )}
+
     </div>
   )
 }

src/components/Dropdown.tsx

@@ -1,11 +1,21 @@
 // 自绘下拉（替代原生 select：原生展开层是系统样式，与应用风格脱节）。
 // 外观对齐 .input；展开层沿用应用菜单语言（面板底、6px 圆角、悬停 --hover、
 // 选中 --accent-weak）；点别处/Esc 关闭走统一的 useDismiss；支持上下键选行。
-import { useCallback, useEffect, useRef, useState } from 'react'
+// 展开层经 Portal 挂到 body 并用 fixed 定位（按触发钮 rect 计算、下方空间
+// 不足时向上翻）：弹窗等带 overflow 的容器里 absolute 定位会被滚动盒裁掉
+// （Git 同步设置里实测被遮挡），Portal + fixed 才能真正逃出裁剪。
+import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
+import { createPortal } from 'react-dom'
 import { useDismiss } from '../hooks/useDismiss'
 
 export interface DropdownOption { value: string; label: string }
 
+interface MenuPos { left: number; top: number; width: number; maxHeight: number }
+
+const ITEM_H = 31
+const MENU_PAD = 8
+const MAX_H = 264
+
 export function Dropdown({ value, options, onChange, disabled, ariaLabel }: {
   value: string
   options: DropdownOption[]
@@ -14,13 +24,35 @@ export function Dropdown({ value, options, onChange, disabled, ariaLabel }: {
   ariaLabel?: string
 }) {
   const [open, setOpen] = useState(false)
+  const [pos, setPos] = useState<MenuPos | null>(null)
   const ref = useRef<HTMLDivElement>(null)
+  const btnRef = useRef<HTMLButtonElement>(null)
   const menuRef = useRef<HTMLDivElement>(null)
   const close = useCallback(() => setOpen(false), [])
-  useDismiss(ref, open, close)
+  const dismissRefs = useMemo(() => [ref, menuRef], [])
+  useDismiss(dismissRefs, open, close)
 
   const current = options.find((o) => o.value === value) ?? options[0]
 
+  // 打开时按触发钮位置算展开层几何：优先向下，下方放不下且上方更宽裕时翻上去
+  const openMenu = useCallback(() => {
+    const rect = btnRef.current?.getBoundingClientRect()
+    if (!rect) { setOpen(true); return }
+    const est = Math.min(MAX_H, options.length * ITEM_H + MENU_PAD)
+    const spaceBelow = window.innerHeight - rect.bottom - 8
+    const spaceAbove = rect.top - 8
+    const above = spaceBelow < est && spaceAbove > spaceBelow
+    const maxHeight = Math.max(80, Math.min(MAX_H, above ? spaceAbove : spaceBelow))
+    const height = Math.min(est, maxHeight)
+    setPos({
+      left: Math.max(4, Math.min(rect.left, window.innerWidth - rect.width - 4)),
+      top: above ? Math.max(4, rect.top - height - 4) : rect.bottom + 4,
+      width: rect.width,
+      maxHeight,
+    })
+    setOpen(true)
+  }, [options.length])
+
   // 打开时把焦点放到选中项，便于直接上下键选行
   useEffect(() => {
     if (!open) return
@@ -29,6 +61,14 @@ export function Dropdown({ value, options, onChange, disabled, ariaLabel }: {
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [open ])
 
+  // 窗口尺寸变化时展开层位置失效，直接关闭（与菜单类组件惯例一致）
+  useEffect(() => {
+    if (!open) return
+    const onResize = () => setOpen(false)
+    window.addEventListener('resize', onResize)
+    return () => window.removeEventListener('resize', onResize)
+  }, [open ])
+
   const pick = (v: string) => { setOpen(false); onChange(v) }
 
   const onMenuKey = (e: React.KeyboardEvent) => {
@@ -46,17 +86,23 @@ export function Dropdown({ value, options, onChange, disabled, ariaLabel }: {
     <div className="dropdown" ref={ref}>
       <button
         type="button"
+        ref={btnRef}
         className="dropdown-button"
         disabled={disabled}
         aria-label={ariaLabel}
         aria-expanded={open}
-        onClick={() => setOpen((o) => !o)}
+        onClick={() => { if (open) setOpen(false); else openMenu() }}
       >
         <span className="dropdown-label">{current?.label ?? ''}</span>
         <svg width="10" height="10" viewBox="0 0 10 10" aria-hidden="true"><path d="M2 3.5 L5 6.5 L8 3.5" fill="none" stroke="currentColor" strokeWidth="1.3" strokeLinecap="round" strokeLinejoin="round" /></svg>
       </button>
-      {open && (
-        <div className="dropdown-menu" ref={menuRef} onKeyDown={onMenuKey}>
+      {open && pos && createPortal(
+        <div
+          className="dropdown-menu"
+          ref={menuRef}
+          onKeyDown={onMenuKey}
+          style={{ position: 'fixed', left: pos.left, top: pos.top, width: pos.width, maxHeight: pos.maxHeight, zIndex: 200 }}
+        >
           {options.map((o) => (
             <button
               key={o.value}
@@ -67,7 +113,8 @@ export function Dropdown({ value, options, onChange, disabled, ariaLabel }: {
               {o.label}
             </button>
           ))}
-        </div>
+        </div>,
+        document.body,
       )}
     </div>
   )

src/components/GitSyncModal.tsx

@@ -45,7 +45,7 @@ export function GitSyncModal({ isRepo, branch, initialRemoteUrl, initialInterval
           <input
             className="input"
             value={remoteUrl}
-            placeholder="https://git.xhome.cc/xieyinlu/notes.git"
+            placeholder="https://github.com/example/example.git"
             onChange={(e) => setRemoteUrl(e.target.value)}
           />
         </label>

src/components/Modals.tsx

@@ -28,6 +28,24 @@ export function ConfirmSaveModal({ title, onSave, onDiscard, onCancel }: {
   )
 }
 
+export function EncodingConvertModal({ encoding, fileName, onConfirm, onCancel }: {
+  encoding: string
+  fileName: string
+  onConfirm: () => void
+  onCancel: () => void
+}) {
+  return (
+    <Shell onCancel={onCancel}>
+      <h3>文档编码将转为 UTF-8</h3>
+      <p>「{fileName}」原是 {encoding} 编码。本编辑器统一以 UTF-8 保存，保存后文件编码将转为 UTF-8（内容不变）。本次运行内，同一文件只提示这一次。</p>
+      <div className="modal-actions">
+        <button onClick={onCancel}>取消保存</button>
+        <button className="primary" onClick={onConfirm}>转为 UTF-8 保存</button>
+      </div>
+    </Shell>
+  )
+}
+
 export function AboutModal({ onClose }: { onClose: () => void }) {
   return (
     <Shell onCancel={onClose}>

src/hooks/useDismiss.ts

@@ -5,12 +5,22 @@ import { useEffect, type RefObject } from 'react'
  * 按 Esc、窗口失焦、或菜单外发生滚动时关闭。
  * 指针监听用捕获阶段：先于 React 的 contextmenu 处理执行，
  * 这样在另一个标签上右键时是「先关旧菜单、再开新菜单」，不会互相冲掉。
+ * refs 可传多个：菜单经 Portal 渲染到 body 时（如下拉展开层），触发器与
+ * 菜单是两个分离的 DOM 子树，两边都算「内」。
  */
-export function useDismiss(ref: RefObject<HTMLElement | null>, active: boolean, onClose: () => void) {
+export function useDismiss(
+  refs: RefObject<HTMLElement | null> | RefObject<HTMLElement | null>[],
+  active: boolean,
+  onClose: () => void,
+) {
   useEffect(() => {
     if (!active) return
-    const outside = (target: EventTarget | null) =>
-      ref.current && target instanceof Node && !ref.current.contains(target)
+    const list = Array.isArray(refs) ? refs : [refs]
+    const outside = (target: EventTarget | null) => {
+      if (!(target instanceof Node)) return false
+      const containers = list.map((r) => r.current).filter(Boolean) as HTMLElement[]
+      return containers.length > 0 && containers.every((el) => !el.contains(target))
+    }
     const onPointer = (e: MouseEvent) => { if (outside(e.target)) onClose() }
     const onKey = (e: KeyboardEvent) => { if (e.key === 'Escape') onClose() }
     const onScroll = (e: Event) => { if (outside(e.target)) onClose() }
@@ -26,5 +36,5 @@ export function useDismiss(ref: RefObject<HTMLElement | null>, active: boolean,
       document.removeEventListener('scroll', onScroll, true)
       window.removeEventListener('blur', onClose)
     }
-  }, [ref, active, onClose])
+  }, [refs, active, onClose])
 }

src/stores/tabs.ts

@@ -46,7 +46,7 @@ export type TabsAction =
   | { type: 'open'; tab: DocTab }
   | { type: 'activate'; id: string }
   | { type: 'updateContent'; id: string; content: string }
-  | { type: 'saved'; id: string; savedContent: string; path?: string; title?: string }
+  | { type: 'saved'; id: string; savedContent: string; path?: string; title?: string; encoding?: string }
   | { type: 'syncEditorContent'; id: string; content: string }
   | { type: 'loadContent'; id: string; content: string; encoding?: string; lineEnding?: string; hadBom?: boolean }
   | { type: 'setPath'; id: string; path: string; title: string }
@@ -93,7 +93,7 @@ export function tabsReducer(state: TabsState, action: TabsAction): TabsState {
         ...state,
         tabs: state.tabs.map((t) =>
           t.id === action.id
-            ? { ...t, savedContent: action.savedContent, path: action.path ?? t.path, title: action.title ?? t.title }
+            ? { ...t, savedContent: action.savedContent, path: action.path ?? t.path, title: action.title ?? t.title, encoding: action.encoding ?? t.encoding }
             : t,
         ),
       }

src/styles.css

@@ -358,7 +358,8 @@ kbd { background: var(--code-bg); border: 1px solid var(--border); border-radius
 .dropdown-button:disabled { opacity: 0.5; cursor: default; }
 .dropdown-button svg { flex: none; color: var(--text-dim); }
 .dropdown-label { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
-.dropdown-menu { position: absolute; top: calc(100% + 4px); left: 0; right: 0; z-index: 60; background: var(--bg-editor); border: 1px solid var(--border); border-radius: 8px; padding: 4px; box-shadow: 0 10px 28px rgba(0,0,0,0.18); display: flex; flex-direction: column; max-height: 264px; overflow-y: auto; }
+/* 展开层几何（fixed 定位/宽/最大高）由 Dropdown 组件内联给出：Portal 到 body 逃出弹窗等 overflow 容器的裁剪 */
+.dropdown-menu { background: var(--bg-editor); border: 1px solid var(--border); border-radius: 8px; padding: 4px; box-shadow: 0 10px 28px rgba(0,0,0,0.18); display: flex; flex-direction: column; overflow-y: auto; }
 .dropdown-menu button { border: 0; background: transparent; color: var(--text); padding: 6px 9px; border-radius: 5px; font-size: 13px; font-family: inherit; text-align: left; cursor: pointer; }
 .dropdown-menu button:hover, .dropdown-menu button:focus-visible { background: var(--hover); outline: none; }
 .dropdown-menu button.selected { background: var(--accent-weak); }

tests/dropdown.test.tsx

@@ -22,18 +22,44 @@ describe('Dropdown', () => {
     const button = container.querySelector('.dropdown-button') as HTMLButtonElement
     expect(button.textContent).toContain('GitHub')
     await act(async () => { button.dispatchEvent(new MouseEvent('click', { bubbles: true })) })
-    const menu = container.querySelector('.dropdown-menu')
+    const menu = document.querySelector('.dropdown-menu')
     expect(menu).not.toBeNull()
     expect(menu?.querySelector('button.selected')?.textContent).toBe('GitHub')
     const notion = [...menu!.querySelectorAll('button')].find((b) => b.textContent === 'Notion')
     await act(async () => { notion?.dispatchEvent(new MouseEvent('click', { bubbles: true })) })
     expect(onChange).toHaveBeenCalledWith('notion')
-    expect(container.querySelector('.dropdown-menu')).toBeNull()
+    expect(document.querySelector('.dropdown-menu')).toBeNull()
     // 再次展开，点别处关闭
     await act(async () => { button.dispatchEvent(new MouseEvent('click', { bubbles: true })) })
-    expect(container.querySelector('.dropdown-menu')).not.toBeNull()
+    expect(document.querySelector('.dropdown-menu')).not.toBeNull()
     await act(async () => { document.body.dispatchEvent(new MouseEvent('mousedown', { bubbles: true })) })
+    expect(document.querySelector('.dropdown-menu')).toBeNull()
+    await act(async () => { root.unmount() })
+    container.remove()
+  })
+
+  it('展开层经 Portal 挂到 body；触发钮靠近窗口底部时向上翻且不溢出', async () => {
+    const container = document.createElement('div')
+    document.body.appendChild(container)
+    const root = createRoot(container)
+    await act(async () => {
+      root.render(<Dropdown value="github" options={OPTIONS} onChange={() => undefined} />)
+    })
+    const button = container.querySelector('.dropdown-button') as HTMLButtonElement
+    // 模拟触发钮贴近窗口底部（jsdom 默认视口高 768）：下方只剩 30px
+    button.getBoundingClientRect = () => ({
+      top: 700, bottom: 730, left: 100, right: 300, width: 200, height: 30, x: 100, y: 700, toJSON: () => ({}),
+    }) as DOMRect
+    await act(async () => { button.dispatchEvent(new MouseEvent('click', { bubbles: true })) })
+    // Portal：菜单不在组件容器内，而是 body 直属
     expect(container.querySelector('.dropdown-menu')).toBeNull()
+    const menu = document.querySelector('.dropdown-menu') as HTMLElement | null
+    expect(menu).not.toBeNull()
+    expect(menu!.style.position).toBe('fixed')
+    // 3 项估算高 101，下方放不下 → 翻到触发钮上方：top = 700 - 101 - 4
+    expect(menu!.style.top).toBe('595px')
+    expect(menu!.style.left).toBe('100px')
+    expect(menu!.style.width).toBe('200px')
     await act(async () => { root.unmount() })
     container.remove()
   })

tests/encoding-modal.test.tsx

@@ -0,0 +1,27 @@
+// docs/29 D1：非 UTF-8 文档保存转码提示弹窗的渲染与回调契约。
+import { describe, it, expect, vi } from 'vitest'
+import { createRoot } from 'react-dom/client'
+import { act } from 'react-dom/test-utils'
+import { EncodingConvertModal } from '../src/components/Modals'
+
+describe('EncodingConvertModal', () => {
+  it('显示原编码与文件名，确认/取消回调正确', async () => {
+    const container = document.createElement('div')
+    document.body.appendChild(container)
+    const root = createRoot(container)
+    const onConfirm = vi.fn()
+    const onCancel = vi.fn()
+    await act(async () => {
+      root.render(<EncodingConvertModal encoding="GBK" fileName="老文档.md" onConfirm={onConfirm} onCancel={onCancel} />)
+    })
+    expect(container.textContent).toContain('GBK')
+    expect(container.textContent).toContain('老文档.md')
+    expect(container.textContent).toContain('转为 UTF-8')
+    const buttons = [...container.querySelectorAll('button')]
+    buttons.find((b) => b.textContent?.includes('转为 UTF-8'))?.click()
+    expect(onConfirm).toHaveBeenCalledTimes(1)
+    buttons.find((b) => b.textContent?.includes('取消'))?.click()
+    expect(onCancel).toHaveBeenCalledTimes(1)
+    await act(async () => { root.unmount() })
+  })
+})