v0.28.3

• Add opt-in syntax-aware bracket pair colours and unmatched-bracket styling to
  Code Editor, with theme hooks for search, selection, matching brackets,
  pop-ups, the current-line bar, and host-owned keyboard shortcuts (#374).
• Refine Process Modeler parity: match reference canvas dots, improve mobile
  toolbar and Checks empty state, and correct View/Escape announcements
  (#322, #326, #329, #330). Riptide host migration and four-view acceptance
  remain open under #321; this release does not claim those issues complete.
• Keep the React, Angular, Vue, and Svelte adapters in lockstep at 0.28.3.