~anthropic/claude-sonnet-latest → A (3:1)

Side A is a coherent, self-contained bugfix: it replaces a silently wrong fallback (unwrap_or(0)) with an explicit invariant check, fixes the actual 0-based vs 1-based indexing bug, updates docs, and adds concrete regression tests verifying the fix. Side B's diff references new modules (crate::html::vote, crate::pair) and routes that are never defined in the shown patch, making it appear incomplete/non-compiling as presented, and mixes unrelated dependency additions (rand, urlencoding) and generated Cargo.lock churn with the actual feature work.