Cataclysm v0.9.0

Universal scenario library and Quick Start milestone. One persistent rail now spans tsunami reference events and complete direct asteroid/nuclear what-if scenarios, with preview-only camera framing, one explicit Run & Watch action, recents, favorites, custom creation, and cross-domain search. Verified locally with 306 unit tests, 51 headless browser journeys, 11 desktop visual baselines, 124 Rust release tests, the strict 24-scene 1440p/4K reference matrix, and a GPU-enabled packaged-binary probe. Installers are currently unsigned and may show a Windows publisher warning.