v0.9.0

• Rename all shipped skills with the hr- prefix. Update skill invocations,
  personal override directories and frontmatter names, exclusions and host
  links. Rule headings and modifier names are unchanged. No old-name aliases
  are shipped. See the upgrade guide.
• Refuse legacy exclusion names and ambiguous personal override names before
  composition writes output. skills.independent records generic personal
  skills intentionally kept alongside their prefixed counterparts.