c06be8f502
* 调整截图按钮默认行为为选区/白板全屏 * 截图选择器新增添加到白板按钮并支持新建白板页插入 * 修复添加到白板不生效:改为剪贴板复制粘贴插入 * 修复添加到白板截图时序:先截到内存再进白板 * Fix screenshot insert flow honoring add-to-whiteboard option * Refine screenshot selector freehand confirm and blank double-click full select * Fix freehand whiteboard insert alpha transparency * Fix screenshot insert notification text for whiteboard flow * Adjust screenshot selection: right-click/double-click full-select and keep selector on single click * Show unmasked freehand selection area like rectangle mode * Remove freehand cutout mask rendering from screenshot selector * Restore freehand selected-area unmask behavior in selector