Folder Previews & Performance Boost

New features

• Added folder content previews within thumbnails
• Added customizable thumbnail aspect ratio options
• Separated folders and files with a line break in Grid and Thumbnail views

Improvements

• Refined thumbnail aspect ratios and sizing
• Improved file loading speeds by fetching subfolder sizes and file counts in parallel
• Excluded hidden and system files from view
• Enabled zooming of file icons using `+` and `-` keyboard shortcuts

Bug fixes

• Fixed localization errors in specific languages
• Fixed an issue where certain file extensions were incorrectly identified as audio