✨ feat(settings-announcements): improve editor UX with modal & tooltips

* Added “Expand Edit” button with `Maximize2` icon to open a large modal editor
* Introduced full-screen `TextArea` modal; content syncs back to main form via Form API
* Switched to correct `TextArea` import from Semi UI to fix invalid element error
* Implemented ellipsis & `Tooltip` for “content” and “extra” columns to keep table concise
* Added state management (`showContentModal`, `formApiRef`) and related handlers
* Updated success messages & punctuation for consistency

web/src/i18n/locales/en.json

@@ -1710,5 +1710,8 @@
   "可信": "Reliable",
   "所有上游数据均可信": "All upstream data is reliable",
   "以下上游数据可能不可信：": "The following upstream data may not be reliable: ",
-  "按倍率类型筛选": "Filter by ratio type"
+  "按倍率类型筛选": "Filter by ratio type",
+  "内容": "Content",
+  "放大编辑": "Expand editor",
+  "编辑公告内容": "Edit announcement content"
 }