Add explorer-middle-click-duplicate mod

[LiHua81]

Summary

• Middle click on empty space in File Explorer to duplicate the current tab in a new tab
• Works on Windows 11 tabbed Explorer
• Detects middle click on empty space via SysListView32 hit-test and DirectUI UIAutomation
• Gets current folder path via IFolderView + IPersistIDList
• Opens new tab via Ctrl+T simulation, then navigates it using the IShellBrowser captured from FileCabinet_CreateViewWindow2

Test plan

• Open File Explorer on Windows 11, navigate to any folder
• Middle click on empty space in the file list area
• Verify a new tab opens in the same window with the same folder path
• Verify middle clicking on a file/folder item does NOT trigger duplication
• Test with multiple tabs already open

Mod authorship

If this pull request introduces a new mod, please complete the section below.

This mod was created by:

• • The submitter, without AI assistance
• • The submitter, with AI assistance
• • Claude
• • ChatGPT
• • Gemini
• • Another AI (please specify):
• • Other (please specify):

Please select the options that best apply. Your selection does not affect the acceptance criteria, but it helps reviewers understand the context of the code and provide relevant feedback.

[m417z]

Thanks for the submission. Instead of having many variations based on the Explorer Double Click Up mod (another example: #4048), it'd be preferable to have a single mod that allows to customize the middle click and double click actions, similar to the way Click on empty taskbar space does it for the taskbar. Will you be willing to enhance the mod and maintain it?