Add launch conversion kit

[MicroMilo]

Summary

• add first-screen download, demo, and community showcase calls to action to both READMEs
• add an outcome-first 14-second 1080p social clip and poster
• state the product promise clearly: open source, local-first, no account, and bring your own model
• link the new community showcase while marking the Chrome Web Store release as coming soon

Verification

• npm run check
• npm run package
• verified the v0.1.1 release asset returns a downloadable ZIP
• verified the social clip is H.264, 1920×1080, 30 fps, and 13.8 seconds