docs(site): refresh the Updates screenshot

[Go2Engle]

Summary

Refresh the Updates screenshot in the feature guide to show the permanent changelog while CriProx is up to date, including the Installed label and earlier releases.

Merge after #109, which adds this app behavior. The screenshot is kept in this separate documentation PR under the repository's website release policy.

Type of Change

Documentation

Technical Details

• Replace docs/assets/criprox-updates.png with the visually verified Updates screen captured using locally simulated desktop state.
• Update the image's descriptive text in the canonical feature guide; the website continues publishing that guide.
• Use a non-breaking docs(site) title and commit so this refresh does not trigger an application release.

Testing Performed

• Visually inspected the screenshot and checked that the installed version and prior releases remain readable.
• Website suite: 17 tests passed.
• Offline website build verified 12 pages and 20 releases.
• git diff --check passed.

npm test --prefix site
npm run build --prefix site -- --offline

Breaking Changes

None. This PR changes documentation and its screenshot.