🎨 Palette: Add ARIA labels to Video Grid controls

[vireapp]

💡 What: Added aria-label attributes to the mobile and desktop control buttons in src/components/room/video-grid.tsx for muting mic, disabling video, and sharing screen.
🎯 Why: These are icon-only buttons, making them completely inaccessible to users navigating via screen readers. Additionally, their state (on/off) dictates their next action, which needs to be properly conveyed.
♿ Accessibility:

• Added dynamic aria-labels based on isMicOn (e.g., "Mute Microphone" vs. "Unmute Microphone").
• Added dynamic aria-labels based on isCamOn (e.g., "Turn Camera Off" vs. "Turn Camera On").
• Added static aria-label ("Share Screen") to the monitor control.

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PR created automatically by Jules for task 5269327211323389357 started by @vireapp

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