Add presentation mode

[hansek]

Extension Submission

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Checklist

• [ x] My folder follows the <author>/<extension-name> convention (lowercase, alphanumeric + hyphens only)
• [ x] I have added an extension.json with all required fields
• [ x] The id field in my extension.json matches my folder path (author.extension-name)
• [ x] I have added an icon file (PNG or JPG, under 100 KB)
• [ x] The icon field in extension.json matches my icon filename
• [ x] My extension is available at the install source I specified (winget/MS Store)
• [ x] I have read the Contributing Guide

Additional context

• Add Presentation Mode to the Command Palette extension gallery
• Install through Microsoft Store
• Provide quick On/Off commands and a live Command Palette Dock toggle
• Include three gallery screenshots