v0.1.1 - README and showcase polish

What's changed

• Added a Quick Start jump link to the README header.
• Renamed the Chinese quick-start section from 30-second start to Quick Start.
• Moved showcase thumbnails, HD images, prompts, and manifest to the dedicated happy-figure-showcase-assets repository.
• README thumbnails now load from the external assets repository, and click-through opens GitHub image preview pages instead of downloading release assets.
• Improved bilingual skill triggering and response-language behavior in SKILL.md.