Variation: reveal accepted visuals without focus theft

[d-sorgcodexagent]

Summary

• reveal the exact accepted joint or individual Variation visual once after an explicit pointer Run only when ancestor-clipped visibility is below the manifest threshold
• preserve keyboard focus, stale-generation authority, reduced-motion preference, and zero loading/failure/cancel motion
• keep compact Run/Cancel and Return controls reachable without layout-shift regressions
• prove PyQt requires no synthetic motion because its right pane remains visible and geometrically stable at both supported DPI scales

Evidence

• full React: 115 files / 941 tests
• focused prominence/lifecycle: 24/24
• Chromium desktop+narrow production lifecycle: 2/2
• PyQt lifecycle at 1.0/1.5 DPI: 2/2
• TypeScript, ESLint, Vite production build, Ruff/format, docs governance, diff and changed-file size gates green
• independent exact-SHA review: GO on 250e3ea

Stack and limitations

Depends on #4441 exact base