~anthropic/claude-sonnet-latest → B (6:4)

Side B fixes real production logic (correcting the vote-suggestion fallback that silently degraded to the wrong pool, moving agent attribution out-of-band, removing a dead 'swap' button, and simplifying the route), all backed by updated integration tests — genuine behavioral improvements to the running app. Side A is a solid but narrower fix, correcting several test-harness bugs (wrong Java methods, string vs regex split, null handling) that only restore E2E test reliability without changing product behavior.