fix(tabs): grouped rail editing review fixes

- Pointer drag: a press released outside the rail no longer lingers. The
  release is heard on window while a press is pending, a move with the
  primary button up cancels it, a new press cancels any previous drag, and
  an existing Escape listener is removed before another is added, so no
  orphaned capture listener can swallow Escape before the terminal.
- Inline group rename: a commit by blur leaves focus where the user put it;
  Enter and Escape still return focus to the header.
- A failed layout read while edits are pending keeps the held layout and the
  editor and re-reads once the write settles, so a 409 is still rebased.
  Dropping unsaved work now always says so in a toast.
- "Move to <group>" quotes the group name (with a matching zh-CN pattern), so
  a group named "New group" or "ungrouped" no longer reads or translates like
  the fixed entries.
- The group menu glyph stays visible under (hover: none).
- The sessionStorage replay copy carries { owner, baseVersion, savedAt } and is
  ignored for another owner, after 60 s, or against an older layout. A move
  with no anchor carries no index, so a replay keeps the row last.
- A 400 that survives the re-read is reported as "Could not save tab groups."
- closeTabRailActionMenu() no longer removes the group menu's DOM.
- Cancelling "Delete group" returns focus to the header.
- Stale comments updated.

src/web/public/i18n.js

@@ -85,6 +85,7 @@
     'Tab groups changed elsewhere; part of your edit no longer applies.':
       '标签分组已在别处更改；你的部分编辑已不再适用。',
     'Tab groups kept changing elsewhere; your edit was not saved.': '标签分组在别处持续更改；你的编辑未保存。',
+    'Your tab group edit was not saved.': '你的标签分组编辑未保存。',
     'Open session manager': '打开会话管理器',
     Attachments: '附件',
     'Open attachment history': '打开附件历史',
@@ -952,7 +953,7 @@
       [/^Selected: (.+)$/, (_m, value) => `已选择：${value}`],
       [/^Failed to (.+)$/, (_m, action) => `操作失败：${action}`],
       // Group names are user text: they pass through untranslated.
-      [/^Move to (.+)$/, (_m, group) => `移到 ${group}`],
+      [/^Move to "(.+)"$/, (_m, group) => `移到“${group}”`],
       [
         /^Delete group "(.+)"\? Its tabs move to Ungrouped\.$/,
         (_m, group) => `删除分组“${group}”？其中的标签将移到未分组。`,