Cosmic Dungeon 1.7.18-alpha.1

This Alpha prepares the artwork for the upcoming responsive help interface.

• Adds 23 lore-based themes covering all 33 current help pages, including distinct backgrounds for the six active classes and references to their original emblems.
• Adds explicit category mapping and aspect-preserving crop metadata.
• Keeps runtime artwork below4MiB; high-resolution masters and review previews stay outside the game JAR.

The existing H screen is unchanged in this artwork preparation batch. The next planned batch integrates the art with the responsive interface and refreshed player guide. No gameplay, class availability, world data, networking or runtime dependency changes. Offline visual checks passed; native interface acceptance remains TESTING after integration.