Support native MacOS shortcuts to move to beginning and end of window

[yasuf]

Adds support to scroll to the top or bottom of the window by using macOS native shortcuts, testing in video.

AI disclaimer: AI used to explore solutions, tested and edited solution proposed by Opus 4.5

testing_macos_3.mov

[yasuf]

the command history doesn't scroll back when I tested so I think we're OK as-is without preventing the event from being sent to Ghostty.

For the page navigation when I do fn + up or fn + down the command history scrolls, that's the main reason why I didn't include that in this PR, the full switch looked like this:

        // Process MacOS native scroll events
        switch selector {
        case #selector(moveToBeginningOfDocument(_:)):
            _ = surfaceModel.perform(action: "scroll_to_top")
        case #selector(moveToEndOfDocument(_:)):
            _ = surfaceModel.perform(action: "scroll_to_bottom")
		case #selector(scrollPageUp(_:)):
            _ = surfaceModel.perform(action: "scroll_page_up")
		case #selector(scrollPageDown(_:)):
            _ = surfaceModel.perform(action: "scroll_page_down")
        default:
            break
        }

[yasuf]

This is part of #2526

[bo2themax]

Looks good to me, only a small suggestion