[seanfinchg]

What changed

Add bio for Sean Finch

Linear issue

Author checklist

• Exactly one new file, bios/firstname-lastname.yml, and nothing else
• Filename is the slug of my name field ("Jane Doe" -> jane-doe.yml)
• Previewed locally (docker compose up --build, or python -m generator serve)
• CI is green (validate-bios, build-site)
• Requested the reviewer named on my Linear issue
• Base branch is testing

Reviewer

Check these four things, then Approve or Request changes:

• Required keys present: name, team, headline, about; team is one
  of the teams listed in site.yml
• Filename matches the author's name and ends in .yml
• about reads professionally — a real sentence or two, no placeholder text
• No files outside this author's own bio were touched

Be specific and kind, comment on the code and not the person, approve when it
is good enough to ship rather than perfect, and save Request changes for a
real blocker.

[linear-code]

LGH-28