Modernize puppet_conf_setting_diffs: OpenVox branding, drop puppet.com links

- Rename title and update all prose to OpenVox Server
- Replace "master" with "server" where referring to the server role
- Remove 31 puppet.com configuration reference links from section headings;
  setting names are retained in backticks
- Update intro to link to OpenVox config reference instead of puppet.com
- Remove legacy canonical frontmatter

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Michael Harp <mike@mikeharp.com>

Author: miharp