CC 2.1.154 adoption

Running binary is 2.1.156, but the substance is all in 2.1.154 (2.1.155 doesn't exist; 2.1.156 = one Opus 4.8 thinking-block fix, N/A). Pick an item.

Snapshots for 2.1.154 + 2.1.156 captured via cc-release-watch. 2.1.153 gap entry stays parse_failed (LLM triage needs an OAuth token, runs via cron — not a parser bug).