feat: implement landing page events section (#917)

[Justber79]

Description

Replaces the landing page’s placeholder Events section with a responsive, API-connected “Upcoming Events” banner.

The section uses the existing Events API, which means events created through the dashboard Calendar can automatically appear on the landing page. It displays the nearest active current or upcoming event in the selected language.

Related Issues

Closes #917

Changes

• Replaced the “Events Section (Coming in landing events section #137)” placeholder
• Connected the section to the existing /event API
• Displayed the nearest active current or upcoming event
• Added the localized event title, short description and date range
• Added responsive background images based on the event type
• Added the “Learn More & Register” CTA
• Added loading and empty states
• Added English and German translations
• Added a fallback URL for CloudFront landing-page assets
• Preserved the existing landing-page styling and responsive layout

Screenshots / Demos

Before

After

Checklist

• WITHIN THE SCOPE OF AN ISSUE; No unnecessary files included
• Tests added/updated
• Documentation updated
• CI passes