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

Side B introduces a substantial architectural change: a composable url_rules engine/registry replacing ad-hoc string canonicalization, making ItemId a real full URL and enabling extensible per-domain rules (reddit, youtube, tracking-param stripping) with broad test coverage across the codebase. Side A is a smaller, valid bugfix restoring OAuth E2E test mocks (regex split, exception handling, correct HttpExchange API), which is useful but narrowly scoped to test infrastructure rather than core product design.