feat: unify settings layout and standardize keybinds

[aninda8680]

Summary

This PR standardizes the web application's user interface and voice controls to perfectly match the desktop client. It completely refactors the Account settings tab into a responsive side-by-side layout and updates the default global voice keybinds for consistency across platforms.

Related issue

Fixes #54

Changes

• Refactored the "Account" tab in DashboardSettings.tsx to use a responsive, side-by-side CSS Grid layout.
• Forced identical vertical stretching between the Account Information and Account Actions cards for perfect visual symmetry.
• Updated the default Toggle Mute keybind to F4 (Key Code 62) in RoomVoiceContext.tsx to standardize the experience with the desktop client.

Testing

• Adjusted window dimensions to verify CSS Grid responsiveness on the Account tab (cards properly stack on small screens and sit side-by-side on large screens).
• Confirmed F4 properly registers as the default mute keybind when mute-keycode is cleared from localStorage.
• Verified that npm run build completes successfully with no rendering errors.

Checklist

• I linked the related issue with Fixes #54 .
• I added or updated tests if needed.
• I updated docs if needed.
• I verified the change locally.

[github-actions]

✅ PR Validation Passed

Your PR title and description meet all requirements:

• Title follows conventional format
• All required sections are present
• Issue is properly linked (callback not working from desktop, chat ui bugs #54)