Add macOS-specific keyboard shortcuts for note navigation

[ishaan-builds]

Description

This PR adds macOS-specific keyboard shortcuts for note navigation and improves the overall keyboard navigation experience. The changes ensure that keyboard shortcuts work consistently across different platforms and match user expectations on macOS.

Changes Made

1. Added macOS-specific keyboard shortcuts:

   • Control + ↑ to select note above
   • Control + ↓ to select note below
   • Control + L to focus on the text editor

2. Updated keyboard shortcuts documentation to reflect these changes.

Testing

• Tested on macOS Sequoia (15.3)
• Verified that shortcuts work when:
  • Text editor is focused
  • List view is focused
  • Search bar is focused

Related Issue

Fixes #186 - Command + arrows doesn't work on Mac

Notes

The changes should maintain backward compatibility while improving the user experience for macOS users. The implementation uses the Control (called META in code) key, which is the standard approach for cross-platform applications.

This fix currently requires that the user disable the default macOS behavior of using Control + ↑ for Mission Control and Control + ↓ to show Application Windows by doing the following:

1. Open System Preferences -> Keyboard -> Keyboard Shortcuts... -> Mission Control
2. Untick the Mission Control and Application Windows

[guihkx]

I just have a few nitpicks....

As for the changes themselves, I'll defer the review to @nuttyartist who is an actual Mac user.

[nuttyartist]

Thanks for contributing!

I must note that I've tested your branch but it doesn't work - probably since built in default shortcuts override your implementation. Here's a video of me pressing control + arrow_down/arrow_up.

Screen.Recording.2025-04-26.at.13.04.26.mov

I'm running macOS 15.4.1.

[ishaan-builds]

Hi! Thanks for taking a look, its my first time contributing to a github project so still working out the kinks.

I got it to work, but only after turning off the default MacOS shortcut for Control + Up and Control + Down in System Preferences -> Keyboard -> Keyboard Shortcuts... -> Mission Control. Without this, the OS captures the input before the app can get it. I'm not sure if turning off that setting is possible through the command line, but I also am not the most informed about that.

Heres a vid on MacOS 15.3

Mac_Testing.mov

[nuttyartist]

I'm happy you chose our project for your first time (:

It's important that our users will not need to change such settings for using our app. So I believe our current implementation (allow focusing the notes list using cmd + shift + L and then use arrow keys) is better. But in the future we'll have a proper settings window that will allow changing keyboard shortcuts, so that's where people could use an approach like yours.