[Robert0622]

Changes

• Restore the original community QR image and place the community section before Contributing in both READMEs.
• Keep the existing GIFs and add playable GitHub-hosted 1080p videos below them.
• Match the English and Chinese attachments to the corresponding README; videos are hosted in issue LoopForge demo videos #59.

Validation

• git diff --check passed.
• python3 scripts/check-public.py passed.
• Both attachments downloaded without authentication and matched the original MP4 files.
• No runtime or packaging changes.