Fix flaky visual tests

A flaky diff comes back changed when nothing actually changed. The screenshot is not lying - it faithfully caught something that moves between runs, like the clock or an animation frame. Remove that source and the flake goes with it.

• The clock - relative timestamps like "2 hours ago", or a date rendered from Date.now().
• Animations - an infinite CSS or JS animation caught mid-frame at a different point each run.
• Live data - a component that fetches a real API renders different content every time.
• Randomness - Math.random, generated ids, shuffled orders.
• Third-party widgets - maps, embeds, ad slots that load their own moving content.
• Web fonts - text captured before the font swaps in reflows on the next run.

• Freeze the clock to a fixed instant so relative-time labels are identical every run.
• Disable or pause animations for the capture.
• Feed components fixture data instead of a live fetch.
• Seed or stub any randomness to a fixed value.
• Stub third-party embeds behind a static placeholder.
• Wait for fonts to load before the screenshot is taken.

For Storybook, control the variation inside the story - fixed props, frozen time, fixture data. For real pages driven by Playwright, archive-replay bakes the page in at record time, so a live API or a feature flag cannot shift it on replay - but you still freeze the clock and stub moving widgets before you record.