feat(e2e): capture the carousel as evidence

[haribo]

Summary

• Third flow of the progressive fill (grow ozalid's own review book, one stable flow at a time #240): judging a capture — the carousel, ozalid's core surface, byte-stable by construction: fixed fixture strings in the bar, a deterministic fixture PNG on the stage, and the carousel covers the page underneath so no case id or date reaches the pixels
• Three steps — facing the capture, weighing a refusal (sheet open, caret blurred out of the bytes), has accepted (filled pair, emerald tint) — both themes, flow video per variant, the fixture variant matching the UI theme
• Signed-in walk (the file's other flows stay signed out); every walk seeds its own case so step three's acceptance never leaks into the next walk

Test plan

• Suite with OZALID_PUSH_SELF=1: 66 passed — the three capture flows pushed their cases, captures and videos through the real API; the double-walk held across a mutating flow
• fe-check, fe-test (109)

No product pixels change — evidence tooling only, no release needed.

Closes #243