- Full SkillDetail.tsx replacing stub (Overview, Versions, Diff tabs)
- Separate installMutation and updateMutation with distinct toast messages
- VersionDiff component using diffLines from diff package
- Version selector with Select dropdowns in Diff tab
- ScrollArea for version list in Versions tab
- Install/Update/Uninstall dialogs with confirmation
- PageSkeleton variant=detail for loading state
- SkillDetail.test.tsx with 4 SSR smoke tests (all passing)
- diff + @types/diff packages installed in ui workspace