🚀 feat: enhance model testing UI with bulk selection, copy & success-filter buttons (#1288)

* ChannelsTable
  - Added row-level checkboxes to the model-testing table for multi-selection
  - Implemented cross-page “Select All / Deselect All” via rowSelection.onSelectAll
  - Introduced allSelectingRef to ignore redundant onChange after onSelectAll
  - Added “Copy Selected” button to copy chosen model names (comma-separated) using helpers.copy
  - Added “Select Successful” button to auto-tick all models that passed testing
  - Moved search bar and new action buttons into the modal title for better UX
  - Centralised page size constant MODEL_TABLE_PAGE_SIZE in channel.constants.js
  - Fixed pagination slicing and auto-page-switch logic during batch testing

* channel.constants
  - Exported MODEL_TABLE_PAGE_SIZE (default 10) for unified pagination control

This commit enables users to conveniently copy or filter successful models, fully supports cross-page bulk operations, and resolves previous selection inconsistencies.

Refs: #1288

web/src/i18n/locales/en.json

@@ -1737,5 +1737,11 @@
   "状态筛选": "Status filter",
   "没有模型可以复制": "No models to copy",
   "模型列表已复制到剪贴板": "Model list copied to clipboard",
-  "复制失败": "Copy failed"
+  "复制失败": "Copy failed",
+  "复制已选": "Copy selected",
+  "选择成功": "Selection successful",
+  "暂无成功模型": "No successful models",
+  "请先选择模型！": "Please select a model first!",
+  "已复制 ${count} 个模型": "Copied ${count} models",
+  "复制失败，请手动复制": "Copy failed, please copy manually"
 }