test(producer): regenerate 8 stale regression baselines in Docker (#1135)

* test(producer): regenerate gsap-letters-render-compat baseline

b2828e48 deferred __renderReady until the root timeline is bound (May 24).
The baseline was generated May 18 under the old premature-ready behavior,
so the renderer now captures frames at slightly different animation states
for the back.out(1.8) letter stagger.  85/100 checkpoints were below the
30 dB PSNR threshold.

Regenerated in Docker with the pinned chrome-headless-shell@148.0.7778.167.

* test(producer): regenerate 7 stale regression baselines in Docker

Runtime changes since last baseline generation caused visual drift in 7 suites.
All regenerated with chrome-headless-shell@148.0.7778.167 inside Dockerfile.test.

Failures before regen:
- many-cuts: 1 frame
- overlay-montage-prod: 1 frame
- pip-video-late-host: 29 frames
- spanish-empire-cdn-inline: 74 frames
- style-18-prod: 24 frames
- style-7-prod: 50 frames
- typegpu-adapter: 75 frames

All 51 suites pass locally after this commit.