* feat: integrate Helicone AI gateway provider
- Add Helicone provider support with automatic model fetching
- Implement custom API logic for Helicone model registry endpoint
- Enable access to 75+ models from multiple AI providers through Helicone gateway
- Add Helicone to supported providers list in README
- Include Helicone configuration in example YAML
* docs: add Helicone to supported providers list
* fix comments
* fixed backgroundless helicone icon asset
* removed unecessesary changes
* replace svg helicone image instead of png
