Make the public site more company-facing

[yunwei37]

What changed

• Rework the About page so it leads with Eunomia Labs, the product/runtime thesis, and how the company builds.
• Move tutorials and public research from the primary About narrative into a lower open-source ecosystem section.
• Update the global footer description to say what Eunomia Labs builds instead of describing the company mainly as the site operator.

Why

The current site has strong technical credibility, but parts of the company-facing surface still read like an OSS/research portal. This keeps the open-source identity while making the company, product direction, and production path clearer to customers, partners, and investors.

Scope

• No homepage thesis changes.
• No URL or routing changes.
• No product/pricing behavior changes.
• English and Chinese copy stay aligned.