[P1] Dialog: No focus return to trigger on close

[sujaypawar]

Summary

Dialog doesn't return focus to trigger button when closed - users lose their place.

Severity: P1 (High)
WCAG: 2.4.3 Focus Order (Level A)
Component: Dialog
File: src/components/dialog/dialog.tsx:104-110

Issue

After closing dialog, focus doesn't return to the button that opened it. Keyboard users must Tab from page start.

User Impact: "I opened a dialog, made changes, closed it. Now I'm back at the top of the page and have to Tab through 50 elements to get back to where I was."

Fix (1 hour)

const triggerRef = useRef<HTMLElement | null>(null);

const handleOpen = () => {
  triggerRef.current = document.activeElement as HTMLElement;
  setOpenState(true);
};

const handleClose = () => {
  setOpenState(false);
  // Return focus after animation
  setTimeout(() => {
    if (triggerRef.current) {
      triggerRef.current.focus();
    }
  }, 300);
};

Testing

• Store trigger element on open
• Return focus on close
• Test with multiple dialogs
• Test with programmatic close
• Verify timing with animation

Related: #369, #371, #375
Priority: P1