Cataclysm v0.8.3

Usability and recovery audit release. Restores stable navigation and solver playback, hardens settings and effect recovery, improves desktop comparison and input workflows, and ships refreshed visual regression coverage. Verified locally with 294 unit tests, 46 browser/visual/WCAG tests, 124 Rust release tests, lint, type checking, security audits, and GPU capability probing.