v4.58.0

Minor Changes

• 6292cc0: Add SplitButton: a button that pairs a primary action with a
  dropdown menu of related secondary actions. The left segment triggers the
  primary action while the chevron on the right opens a menu of DropDownOption
  children. Both segments share a single variant/size.

  It composes existing primitives (Button, Flyout, DropDownOptionsList,
  DropDownOption) and follows the WAI-ARIA split button pattern: two
  independent buttons in a role="group", with the trigger exposing
  aria-haspopup/aria-expanded and Escape-to-close.

  Button was also extended to accept and forward onKeyDown and the
  aria-controls/aria-expanded/aria-haspopup attributes, which menu and
  disclosure patterns require. This is additive and backwards compatible.

• 86cd7cf: Upgrade @autoguru/icons to 2.0.1 (Phosphor-style redesign) and
  bump the peer dependency floor to >=2.0.0.

  @autoguru/icons@2.0.x renames/removes a number of icons, so every internal
  usage in the library was migrated to the new names (e.g. Chevron* →
  Caret*, Close/WindowClose → X, Magnify → MagnifyingGlass, Email
  → Envelope, Settings → Gear, Sort → ArrowsDownUp, StoreOutline →
  Storefront, TrashCanOutline → Trash, Alert → Warning). No public
  component API changed.

  The Foundation/Icon Set story was also rebuilt with a live name search and
  icons grouped into the design-system categories from the DS 2026 Figma.

  Note: consumers still on @autoguru/icons 1.x must upgrade to 2.0.1.
  Reviewers may wish to release this as a major bump if that peer-dependency
  change is treated as breaking for downstream apps.