Root cause: Constellation indexes posts by their DID-form at-uri, but when a post is opened the thread receives a handle-form anchor uri (at://handle/...) from the route. Every Constellation backlink lookup against the handle form returns 0 (verified live: handle -> total 0, DID -> total 14), so the anchor had zero counts and reply backlinks found nothing -> no stats, no comments. Feeds were unaffected because their uris come from records already in DID form. Fixes: - hydratePost and buildPostThread now resolve a handle authority to a DID (via MiniDoc) before any Constellation/record lookup. - Thread replies and ancestors hydrate in full (not lite) so they show their own like/reply/repost counts and viewer state, like the AppView. Reply volume is bounded by branchingFactor. - Dropped the User-Agent header from the Constellation/Slingshot fetch clients (browsers forbid setting it; harmless cleanup).