a3f387fa2a
DB/API already supported arbitrary-depth replies via the self-referencing parentId, but the UI only rendered top-level + one reply level — a reply-to-a-reply was fetched but never shown. Rewrite CommentItem as a recursive component keyed off a parentId->children map; visual indent caps at 4 levels (Reddit-style flatten) but nesting itself is unbounded. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>