fix: 合并 main 后的测试回归修复

- index.ts: 移除 #130 遗留的 ctx.on('session/disposed')（fake ctx 无 on，
  且 #130 已按取 HEAD 决策，closeSession 调用方一并移除）
- browser.probe: 405→GET 重试后跳过 embed-signals GET，避免多余第 3 次请求（#69）
- EditorHost: 移植 #228 的 dirty 确认守卫到 HEAD 的 reloadSeq 结构（refreshFile）
- tests: fake ctx 补 get()（#357 ctx.get 回归，free-window/editor-refresh/markdown）
- tests: prefs 期望对象补 browserAllowedLoopback（smoke/plugin-shape/state）
- tests: builtins 浏览器设置行补 browserAllowedLoopback（#69）
- tests: install-powershell BOM 门限仅对实际文档化远程调用的文件生效
- locales: 19 语言补齐 showInFolder / refreshUnsavedConfirm（#94 #215 #228）

src/client/EditorHost.tsx

@@ -113,6 +113,18 @@ export function EditorHost(props: {
   // with the same path/scope — the only reload entry besides open/close.
   const [reloadSeq, setReloadSeq] = useState(0)
 
+  // Manual refresh (issue #167 + PR #228): a dirty draft is dropped by the
+  // reload (the editor instance remounts), so confirm before discarding it.
+  const refreshFile = (): void => {
+    if (toolbar?.dirty === true) {
+      const confirmed = typeof window.confirm === 'function'
+        ? window.confirm(t('refreshUnsavedConfirm'))
+        : false
+      if (!confirmed) return
+    }
+    setReloadSeq(sequence => sequence + 1)
+  }
+
   // Reactive prefs read: flipping editorExplorer re-renders this tab with no
   // reload. The snapshot is the bare boolean so unrelated store churn never
   // re-renders the editor.
@@ -426,7 +438,7 @@ export function EditorHost(props: {
             className={css.iconButton}
             aria-label={t('refresh')}
             title={t('refresh')}
-            onClick={() => { setReloadSeq(sequence => sequence + 1) }}
+            onClick={refreshFile}
           >
             <IconRefreshOutline14 size={14} />
           </button>