fix(a11y): Fix tab order to match visual/logical reading order

[AbhiAditya02]

Description

This PR resolves the critical accessibility issue where the keyboard focus order (Tab sequence) did not align with the visual and logical reading order of the video editor application.

Core Changes

• DOM Focus Alignment: Restructured JSX elements inside VideoEditor.tsx to align sequential tab order logically (Upload → Preset → Framing → Trim → Rotate → Audio → Quality → Export).
• Prism Layout Preservation: Absolute-positioned the right-column blocks on desktop to keep the visual two-column layout intact with zero vertical gaps or overlaps.
• Synchronized Sticky Column: Added React observers and a window scroll/resize listener to cleanly stick both right-hand cards in synchrony until the left column finishes.
• Hydration Flicker Guard: Set default states to 0 and applied a desktop opacity transition to eliminate split-second layout shifts or overlaps on reload.
• Unit Testing: Added a dedicated accessibility tab-order test suite (VideoEditorTabOrder.test.tsx) to assert proper sequential ordering. All tests passed.

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Related Issue

closes #167

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Type of Contribution

• Bug fix
• New feature
• Documentation update
• Refactor
• GSSoC contribution

Participant Info

• GitHub username: @AbhiAditya02
• Contribution level : Intermediate

Screen Recording

Screencast.from.2026-05-30.17-09-44.webm

Checklist

• I have read the contribution guidelines
• My changes follow the project structure
• I have tested my changes in Chrome, Firefox, and Safari
• bun run lint passes (no ESLint errors)
• bunx tsc --noEmit passes (no TypeScript errors)
• New interactive elements have aria-label / accessible names
• No console.log statements left in
• This PR is related to a valid issue
• Screen recording attached above (required for UI/feature/design changes)

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[github-actions]

👋 Thanks for your PR, @AbhiAditya02!

Welcome to Reframe — a browser-based video editor built for everyone 🎬

🟠 GSSoC'26 PR detected — thanks for contributing under GirlScript Summer of Code 2026!

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