SD-20 Move FAQ content into translations and add Help entry point

[SamuelEmery]

Summary

This PR moves the Help/FAQ page content out of CMS-driven frontend content and into the React i18n translation layer so it can be managed through Weblate. It also adds a clearer entry
point to the Help page from the landing page.

Changes

• replaced the FAQ markdown/CMS rendering flow with a dedicated FaqContent component backed by translation keys
• added the full English FAQ copy, including inline links and help images, to translations.json
• updated the /help page to render translated content directly instead of fetching frontend content
• made the Help page route publicly accessible and added a Help button with icon in the landing page navigation
• added FAQ-specific styling for section headers, spacing, blockquotes, and images
• removed the now-unused markdown helper that rendered FAQ text from frontend content
• added a test for FaqContent and updated the landing page snapshot

Why

The FAQ content needs to be translatable through Weblate, and the previous CMS/frontend-content approach was not a good fit for that workflow.

Testing

• added FaqContent render coverage for translated headings, links, and images
• updated landing page snapshot for the new Help navigation item