🐛 Preserve screenshot capture geometry

[Robdel12]

Why

The screenshot client accepted harness capture facts such as the coordinate mode, device scale factor, and element selector, but normalization dropped them before the cloud request. That left the API without the source facts it needs to build reliable screenshot identities or translate Honeydiff regions into CSS coordinates.

What changed

• Preserve captureMode, deviceScaleFactor, and selector as reserved screenshot options in the cloud properties payload.
• Promote the same fields from the legacy nested properties shape with the existing reserved-option warning behavior.
• Document the public JavaScript and TypeScript contracts.
• Cover the real request payload at the HTTP boundary.

Confidence

The full CLI suite passes (2,321 passing, 5 skipped), the production build completes, and the published type definitions pass their contract checks.

[Robdel12]

This browser-capture contract is superseded by the bitmap-native design. Vizzly must accept raw screenshots from any platform without requiring browser-specific capture metadata.