New demo booking and media features added

Added:

• You can now book a demo using a quick scheduling interface in the header.
• More avatar choices are available for creating UGC videos.
• Generate professional product photoshoots from reference images.
  Improved:
• Translations updated for the new demo booking feature in multiple languages.
• UI now shows clearer feedback when uploading or loading content.
• API service rate limits enhanced for smoother usage during traffic spikes.
  Fixed:
• Validation and error messages improved for promotional video creation.
• Email input now limits to 5 addresses for better form usability.