openai/gpt-chat-latest → B (4:1)

Side B makes a substantive architectural cleanup by removing legacy GitDiscovery projection paths, requiring evidence metadata in `Emission`, simplifying epoch/commit endpoints to use Evidence envelopes only, and updating tests to enforce the new model. Side A is primarily a refactor that replaces the old URL engine with new graph/parse modules and updates documentation and tests, but the patch shown mostly removes the previous implementation while delegating behavior elsewhere, making its lasting functional impact less directly evident.