- APIClient: generate and persist a stable device UUID (jarvis.device.id in UserDefaults); attach as X-Jarvis-Device-Id header on every request - Add markStoryRead / markStoryUnread — POST/DELETE /stories/:id/read with device_id, read_at, and source fields - Wire both calls into all three read-toggle sites: SignalFeedView, ArticleReaderView, StoryDetailView - Add postVoid helper for fire-and-forget POST calls (no response body needed) - Pass include_read param on stories fetch for future server-side filtering - CacheMaintenance: recentHours 84→72 (mirrors backend 72h story window); markerHours 96→192 so read suppression survives a full weekly news cycle Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>