• Updated EuiPageSidebar and EuiPageTemplate.Sidebar with a new hasEmbellish prop (defaults to false) (#7521)
• Added diff glyph to EuiIcon (#7520)
• Added newChat glyph to EuiIcon (#7524)

Bug fixes

• Fixed EuiSideNav not correctly typing the items prop as required (#7521)
• Fixed the CSS is not defined bug in EuiPageTemplate when rendering in some SSR environments, particularly Next.js v13 and up (#7525)
• Fixed EuiDataGrid component to clean up timer from side effect on unmount (#7534)

Accessibility

• Fixed EuiSideNav to render a fallback aria-label on mobile toggles if no heading or mobile title exists (#7521)

CSS-in-JS conversions

• Converted EuiSideNav to Emotion; Removed the following Sass variables: (#7521)
  • $euiSideNavEmphasizedBackgroundColor
  • $euiSideNavRootTextcolor
  • $euiSideNavBranchTextcolor
  • $euiSideNavSelectedTextcolor
  • $euiSideNavDisabledTextcolor
• Removed the euiSideNavEmbellish Sass mixin. Use the new EuiPageSidebar hasEmbellish prop instead (#7521)
• Added a new memoization/performance optimization utility for CSS-in-JS styles (#7529)