~anthropic/claude-sonnet-latest → B (3:2)

Side B fixes a real production NameError in the actual application code (missing GITHUB_API_BASE_URL definition), directly preventing a crash in the OAuth callback path. Side A's changes, while more extensive, are confined to test infrastructure/mocks—valuable for test reliability but not fixing a production defect; it also introduces a subtle regression risk by using 0 instead of -1 for redirect content-length without clear justification.