TREK: Stored cross-user HTML injection via trip title in the Journey suggestion banner

TREK is a collaborative travel planner. Prior to 3.1.0, when the Journey add-on is enabled, TREK interpolates the unescaped activeSuggestion.title value into journey.frontpage.suggestionText through client/src/i18n/TranslationContext.tsx and renders the result with dangerouslySetInnerHTML in client/src/pages/JourneyPage.tsx. A trip owner can store HTML in a qualifying trip title, and GET /api/journeys/suggestions returns that title through getSuggestions(userId) to a collaborator who opens the authenticated Journey page. The markup is inserted as live DOM in the collaborator's session, enabling content spoofing and UI redress, although the default Content Security Policy blocks inline handlers and script execution. This issue is fixed in version 3.1.0.