openai/gpt-5.3-chat → A (6:5)

Commit A is a deep, cross-cutting architectural change introducing a full URL canonicalization system (url_rules engine, registry, and integration into ItemId) and migrating the entire codebase to canonical URL identities. It modifies core data modeling, parsing, storage, and many call sites, making it foundational. Commit B is also substantial—adding a resolver framework, GitHub import cards, UI rendering, and fixing the external index—but it is more feature-oriented and layered on top of existing structures. A has broader systemic impact, while B is a large but more modular feature addition.