add Wikontic demo presentation animations

[yurakuratov]

Adds a standalone Wikontic demo presentation built with React + Remotion.

The demo contains three short, independently renderable animations and a browser presentation viewer for demo use:

• text to ontology-aligned knowledge graph
• RAG vs Wikontic for multi-hop QA
• graph-based synthetic data generation
• and summary with key metrics

What changed

• Added wikontic-demo-animation/ project with Remotion compositions and Vite presentation viewer.
• Added EN/RU localized demo content, with English as default and a language toggle.
• Added presentation controls: autoplay per slide, pause/resume, restart, chapter jumps, frame stepping.
• Added final metrics slide covering interpretability, graph-only QA, and token economy.
• Added deterministic hardcoded data only; no backend or live API calls.
• Added README with setup, preview, render, and maintenance instructions.

Validation

• npm run check
• Manual presentation preview via npm run present