Add ChatUserProfile record and IViewerRepository.LoadChatProfilesAsync (AsNoTracking,
projects Name/EmblemId/CountryCode/Rank/DegreeId from Viewer+Info nav refs).
GuildChatController.Messages now injects IViewerRepository instead of SVSimDbContext;
calls LoadChatProfilesAsync to populate users[] (removes direct db access from controller).
GuildChatMessageRepository direction=2 (NEW): change >= start to > start (exclusive).
GuildChatPollTests updated to assert the start message is NOT returned by direction=NEW.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>