openai/gpt-chat-latest → B (9:1)

Side B adds a substantial new URL canonicalization subsystem: a graph/DFA-based resolver with parsing, graph builder validation, generic fallback logic, Reddit/YouTube canonicalization, breadcrumb generation, and extensive unit/end-to-end tests covering normalization, encoding, aliases, and regressions. Side A only removes a now-redundant zero-ratio guard from `apply_vote` and updates the test expectations to reflect that zero-weight edges are skipped later while items are still registered.