Editor keyboard navigation

We've completely overhauled how the keyboard works inside the image editor, making it possible to fly through edits without touching the mouse.

• Navigate everything: Use the Up and Down arrows to move between control groups (like Brightness to Contrast), and Left and Right to adjust the sliders.
• Cycle assets and versions: When you aren't actively editing a value, Left and Right cycle through your library's images, while Up and Down cycle through the saved versions of the current image.
• Smarter Escape: Hitting Escape now follows a logical priority — it closes the active popup first, then discards edits, and finally closes the editor, rather than doing it all at once.
• Quick save and rename: Hitting Enter while renaming a version now commits the name and saves the version in a single keystroke.
• Cmd/Ctrl + S: Hit Cmd / Ctrl + S anywhere you're viewing an asset to download it instantly. If you have unsaved edits open, it will save your new version instead. No more reaching for the menu.