openai/gpt-chat-latest → A (5:1)

Side A replaces the URL canonicalization architecture from ad hoc normalization functions in `engine.rs` with a graph-based API (`graph`/`parse`) and updates the public registry to delegate canonicalization and breadcrumb generation through that abstraction, along with documentation and test module reorganization. Side B only removes a redundant zero-ratio guard in `apply_vote` and adjusts the corresponding test expectations, which is a small cleanup with limited long-term impact.