~anthropic/claude-sonnet-latest → A (8:2)

Side A is a focused, verified correctness fix: it removes a silent unwrap_or(0) fallback that masked invariant violations, replaces it with an explicit expect, aligns doc comments/URLs to the actual 0-indexed semantics, and adds concrete integration tests validating thread_post_index behavior. Side B mostly dumps unintegrated scaffolding (event_log.rs and views.rs at repo root, not wired into any module tree) plus deployment config and an unrelated Clojure deps.edn, with no tests and unclear integration into the existing Rust crate structure.