Zemeroth source and adaptations

Frozen official browser binary/assets; v0.6 source reference at 75dbf2e2332ec246ee49d1398e8db42635c50368. The source archive omits the unused decorative repository logo. This reference is not an exact-build reproducibility claim for the published browser binary.

• Licensed game source reference
• good-web-game source reference
• gl-rs source reference
• Unmodified browser bootstrap
• Readable keyboard/lifecycle adapter
• Adapted player HTML
• Presentation styles
• Licenses and changes
• Dependency notice records