v2.1.0

What's new

• Unified project persistence across client export/import, autosave, and server API.
• Fixed arrangement interactions when the timeline is horizontally scrolled.
• Fixed transport and preview sync, including loop-aware playhead starts and clean scheduler handoff.
• Added lazy loading and chunk splitting for heavy frontend panels.
• Added ESLint, tests, CI, and the npm verify workflow.

Validation

• npm run lint
• npm test
• npm run build