wave-chain.sh: commit subject now comes from tasks/<task>.subject instead of being hard-coded for waves 9/10; drop a stale session trailer. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01RWoivrRUEmJLFFwbsrGkqQ