Optimize window position for vertical task bar on Windows 10

[kot149]

Description

With vertical taskbar on Windows 10, the window may be hidden by the taskbar.

Environment

Windows 10 with vertical taskbar

Suggested Improvements

Window positioning is totally relying on Tauri Positioner plugin and I 'm not sure if it is compatible with vertical taskbar.
An alternative would be to allow users to manually adjust the window position.

[kot149]

I mistakenly mentioned in the PR; it is not related

[kot149]

I've confirmed that the Tauri Positioner plugin is not compatible with vertical taskbars. Its TrayRight/Left options align the bottom-left corner of the window with the top-right/left corner of the tray icon, which does not produce the expected positioning.
While this could be fixed by forking and modifying the plugin, I decided against this approach due to the complexity of understanding the implementation fully and the associated maintenance costs.

Instead, I've implemented a workaround in PR #7 that allows users to manually adjust the window position.
Please refer to the troubleshooting section in the README for detailed instructions on how to use this feature.