Update stale (118) → 137 unique-slot count and [174..294) = 120 → [174..313) = 139 range in the SP5_PRODUCER_COUNT docstring. Update inline comment unique-slot count 121 → 137 with SP7 T1 breakdown entry. Append SP7 Task 1 history paragraph matching the established Layer D D3 paragraph style. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>