Add a Gateway Decisions section to PP-001: S01 decided Go on both gateways on
2026-10-08, ahead of the planned 2026-10-09 and 2026-10-14, because every Go
criterion was already met. Each row names the criteria, the review record
(RC-005, RC-006) and the merged pull request (#14, #16).
Close the reference-image open issue, which has been resolved since S01
supplied the image on 2026-10-07. The two open decisions on RC-006 (the display
requirement of the tests, the pale palette colours) did not block either gate.