Flickr now refuses hotlinked original-size (_o) images with HTTP 429, so every carousel and gallery image sourced from an external Flickr album failed to load. The same photo at any smaller size loads fine with the same secret, so rewrite _o URLs to the 1024px _b size in UrlService.imageSource, the single point all image URLs pass through.
Applies at render time to existing stored data, so no re-scrape or re-import is needed, and only Flickr static-CDN originals are touched.
Renames the Jitsi token helpers to issueMeetingToken / issueGuestToken / IssueMeetingTokenOptions across the server and updates the jitsi README wording. Adds unit tests for JWT issuing (jitsi-jwt.spec) and the meeting-invite ICS builder (meetingIcalDocument in ical.spec).