[datlechin]

Summary

• Sponsors section shows each homepage sponsor's logo, linked, instead of bold names. Adds Pyto.
• Individual sponsors listed by name.
• Links to tablepro.app/sponsors, which has the tiers. README.vi.md and README.zh.md get the same section and link the page in their language.
• Logos sit on white tiles in .github/assets/sponsors/, so the black wordmarks stay visible in GitHub's dark theme. Generated from the site's files by the sponsors skill in TableProApp/web.

Test plan

• Rendered the five tiles on GitHub's light (#ffffff) and dark (#0d1117) backgrounds: all load, none is lost on dark.
• Merge after feat(sponsors): add a sponsors page with tiers and the open homepage places web#128 deploys, so the sponsors page links answer.