i18n(sidebar): translate the folder delete verification strings

Fills in the 9 locale renderings for the 5 keys added with the folder delete
verification (`sidebar.deleteFolderModal.notEmptyMessageCount`,
`.notEmptyMessageExcluded`, `.busyTitle`, `.checking` and
`sidebar.deleteFolderResult.notEmptyWithCount`), so no `[TODO: Translate]`
placeholder remains anywhere.

Each locale reuses its existing `notEmptyMessage` cascade clause verbatim
(punctuation included) and its help-text style for quoting the "Manage
Excluded Models" label; `{count}` / `{excluded}` match en.json. The Hebrew
model-file noun stays `קובצי מודלים` across all four keys.
docs/i18n-translation-guidelines.md records the new copy in §2 and refreshes
its stale `{count}` and leaf-key counts.

locales/zh-CN.json

@@ -1350,10 +1350,10 @@
             "emptyNote": "该文件夹中没有模型，其中的其他文件也会一并删除。",
             "notEmptyTitle": "文件夹不为空",
             "notEmptyMessage": "该文件夹中仍有模型，请先删除或移出这些模型 —— 删除文件夹不会级联删除模型文件。",
-            "notEmptyMessageCount": "[TODO: Translate] This folder still contains {count} model file(s). Delete or move them first — deleting a folder never cascades over model files.",
-            "notEmptyMessageExcluded": "[TODO: Translate] This folder still contains {count} model file(s), {excluded} of them excluded from the library. Un-exclude them in Manage Excluded Models and delete them first — deleting a folder never cascades over model files.",
-            "busyTitle": "[TODO: Translate] A deletion is still pending",
-            "checking": "[TODO: Translate] Checking the folder contents...",
+            "notEmptyMessageCount": "该文件夹中仍有 {count} 个模型文件，请先删除或移出这些模型 —— 删除文件夹不会级联删除模型文件。",
+            "notEmptyMessageExcluded": "该文件夹中仍有 {count} 个模型文件，其中 {excluded} 个已从模型库中排除。请先在“管理已排除的模型”中取消排除并删除它们 —— 删除文件夹不会级联删除模型文件。",
+            "busyTitle": "仍有删除操作待处理",
+            "checking": "正在检查文件夹内容...",
             "confirm": "删除文件夹"
         },
         "deleteFolderResult": {
@@ -1362,7 +1362,7 @@
             "restored": "文件夹已恢复",
             "failed": "删除文件夹失败: {message}",
             "notEmpty": "该文件夹中仍有模型。请刷新侧边栏后重试。",
-            "notEmptyWithCount": "[TODO: Translate] This folder still contains {count} model file(s). Refresh the sidebar and try again.",
+            "notEmptyWithCount": "该文件夹中仍有 {count} 个模型文件。请刷新侧边栏后重试。",
             "busy": "该文件夹内仍有待处理的删除操作，请等待撤销窗口结束。",
             "unsupported": "此页面不支持删除文件夹",
             "noRoot": "未配置模型根目录"