Redesign export video dialog

Wider dialog with labeled sections, quality comparison cards, a pages
panel with row toggles and select-all, and a live summary sharing the
bottom row with the actions. Hierarchy comes from size and color, not
weight. Step duration now clamps to 1-15s (ADR 0003 updated).
5d4630dfd7Dara Adedeji committed on 8/16/2026, 4:18:36 AMparent30d1379

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