[daveh-beep]

Summary

David Hamilton’s blog author profile needs an updated title and is missing an X link.

• Change the byline to “Principal Designer, Block”.
• Add https://x.com/writesdavid through the existing socials.x field.
• Leave post content, the author identifier, and existing profile links unchanged.

This changes only documentation/blog/authors.yml and updates the shared profile across the blog.

Validation

• Passed DOCS_BASE_URL=/governed-artifact-protocol/ pnpm docs:build.
• Passed pnpm docs:test (16 tests).
• Passed pnpm --dir documentation typecheck.
• Checked the generated HTML for “Hello World” and David’s author page: both contain the updated byline and https://x.com/writesdavid, retain the existing GitHub and LinkedIn links, and omit the old byline.
• Passed git diff --check.