fix(整合): 再次提升更新日志模态框层级至最高优先级

- 将背景遮罩 z-index 从 z-[100] 提升到 z-[9999]
- 将模态框内容 z-index 从 z-[101] 提升到 z-[10000]
- 确保模态框在所有可能的元素之上显示，包括 Header 搜索下拉等

via [HAPI](https://hapi.run)

Co-Authored-By: HAPI <noreply@hapi.run>

src/data/changelog.json

@@ -1,5 +1,12 @@
 {
   "changelogEntries": [
+    {
+      "id": "2026-03-08-fix-modal-zindex-again",
+      "date": "2026-03-08",
+      "type": "fix",
+      "title": "再次提升更新日志模态框层级至最高优先级",
+      "scope": "整合"
+    },
     {
       "id": "2026-03-08-fix-modal-zindex",
       "date": "2026-03-08",