fix: scope focus scale to inner wrapper to avoid layout reflow

[MrSimmo]

MrSimmo-FIX-CHANGES.md
Replace 'transition: all' on .itemCard with 'transition: transform' on a new .itemCardInner element. Eliminates CPU reflow during focus animations on lower-power Smart TV hardware. Applied symmetrically to Favorites and Library views.

Pull Request

Summary

I've attempted to fix the issue I reported in https://github.com/Moonfin-Client/Smart-TV/issues/111#issuecomment-4270176875. I used Claude Code so please do verify before merging. If it's possible to share a test version for the people reporting the same before the merge, it would be useful - keen not to introduce other issues.

I have also included a markdown with the changes proposed, in the PR.

Related Issues

https://github.com/Moonfin-Client/Smart-TV/issues/111#issuecomment-4270176875

• Closes #
• Fixes #
• Related to #

Type of Change

• [ x] Bug fix
• New feature
• Refactor
• Performance improvement
• [x ] UI/UX update
• Documentation update
• Build/CI change
• Other (describe):

Changes Made

List the key changes included in this PR.

• UI scrolling changes to Library and Favourites views.

Platform

• [x ] Tizen (Samsung)
• webOS (LG)
• Both / Shared code

Testing

Describe how this change was tested.

• [x ] Tested on emulator
• Tested on physical device
• Manual testing completed
• [x ] Not tested (explain why): Virtual testing on local dev, not tested on TV as yet.

Test Steps

1. Push updated package to Samsung Tizen 5
2. Open package
3. Check UI scrolling

Screenshots (if applicable)

Include screenshots or recordings for UI changes.

Checklist

• Code builds successfully
• Code follows project style and conventions
• No unnecessary commented-out code
• No new warnings introduced