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

Side B fixes a real off-by-one bug (thread_post_index was incorrectly 1-indexed with a fallback masking missing entries) with corrected docs and new regression tests covering the exact indices, giving lasting correctness value. Side A is a useful but purely mechanical config simplification (collapsing two hand-listed kaocha suites into a wildcard pattern) with no bugfix and lower risk/benefit.