EasyPresent Desktop

## EasyPresent v3.8.1 — Canva Manager style polish

This patch polishes the Canva Manager interface so it better matches the existing EasyPresent drawer/table style.

### Changed files
- package.json
- package-lock.json
- src/frontend/components/drawer/shows/CanvaManager.svelte
- release-notes/v3.8.1.md

### Changes
- Improved Canva Manager styling.
- Made the Canva Manager area more compact and consistent with the app interface.
- Kept Add, Edit, Save, Open, and Delete behavior unchanged.
- No Remote, Canva output, Songs, Bible, or presentation playback logic changed.

### Test checklist
- App opens normally.
- Version shows 3.8.1.
- Presentations → Canva opens correctly.
- Canva Manager follows the app style.
- Add Canva link works.
- Select saved Canva item works.
- Save, Open, and Delete still work.
- Saved Canva links still present correctly.
- Remote next/previous still works.