Add `website` to `/info` response when configured

[0xNgoo]

Summary

The /info response surfaces the anchor name and optional support email, but it does not surface the configured website.

Why this matters

Including the website gives integrators a conventional place to link to the anchor's main site when configured.

Task

• Add a website field to the /info response when operational.website is configured.
• Omit the field entirely when no website is configured.

Acceptance criteria

• A configured website appears in the /info response.
• The field is omitted, not set to null, when no website is configured.

Testing notes

• Add or update focused tests for the behavior in this issue.
• Run bun test before opening the pull request.
• Add or update an integration test that covers both the configured and omitted cases.

Contributor notes

• Keep the change narrowly scoped to the behavior described above.
• Use Bun for commands and TypeScript for any code changes.
• Avoid adding new runtime dependencies for this issue.