publish: MOI 5.0 正式开启公测

[dengn]

Summary

• Add the Chinese MOI 5.0 public beta launch article to the MatrixOrigin company blog.
• Include the seven article images migrated from the prototype repository and reference them with article-local paths.
• Publish the article with registration, product entry points, public beta benefits, feedback guidance, and Gartner recognition.

Verification

• pnpm validate — Checked 387 files: 387 ok, 0 with issues.
• git diff --cached --check
• Confirmed every ./images/ reference resolves to an article-local asset.

Issue

None.

Scope Notes

• Target project directory: matrixorigin/
• Changed article slug: moi-5-public-beta-launch
• Publish status changes: adds one article with status: published
• Downstream deploy behavior changed: no

Known Notes

• This PR contains Chinese content only; no English counterpart is included.