~anthropic/claude-sonnet-latest → B (65:35)

Side B performs the foundational integration: it introduces the url_rules engine/registry, switches ItemId to store fully-qualified canonical URLs, and updates every call site across the codebase (event_log, journal, pair, parser, projection_apply, reddit.rs, reducer, render, state) plus docs and a replay script, fixing real correctness issues (scheme-qualified IDs, parent/breadcrumb logic). Side A largely re-implements the same URL-parsing/canonicalization logic as a DFA graph with extensive tests, but it only touches files inside url_rules and isn't wired into the rest of the system, making its practical impact less certain and partly redundant with the machinery B already built.