Reconciled with #470 (PGXP): gpu.c precise vertices take PGXP only under geometry correction and count it, then native-wide edge recovery; the PGXP triangle stat stays PGXP-only. Stubs and tests from both kept; stamps recomputed.
Master moved the textured-dot test stubs into gpu_exec_stubs.inc; the PGXP stubs move there too. pgxp_note_rect_bypass stub takes (int). Stamps recomputed.
Letterbox bars squashed as HUD left the revealed margins showing the frame's clear colour. Also link gpu_timeline.c into the GPU exec tests (broken since b2104464).
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>