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

B fixes a real correctness bug (timestamp-based feed cutoffs failing under same-millisecond posts and clock rollback) and closes a permission-leak edge case for private rooms, backed by substantial integration tests exercising these exact scenarios. A refines pair-selection heuristics for a ranking algorithm with good test coverage, but it's an optimization/tuning change rather than a bugfix, and its value is more speculative/UX-quality than correctness-critical.