Add Rive vector animation runtime

[Sportinger]

Summary

• Add Rive WASM runtime support for .riv import, timeline clips, rendering, export, thumbnails, persistence, and background render paths.
• Extend the vector animation property panel for Rive artboards, animations, state machines, events, loading assets, and Data Binding values.
• Add Rive data-binding keyframe paths and update vector-animation docs/tests.

Verification

• npm run build
• npm run lint
• npm run test

Refs #137