[Sammyzyandev]

Summary

• Add an explicit accessible name for modal dialogs without visible titles.
• Exclude disabled, hidden, and aria-disabled controls from the focus sequence.
• Redirect Tab focus back into the dialog if focus has moved outside, and keep the existing first/last focus wrapping and focus restoration.
• Add tests for dialog naming, initial focus, both Tab directions, and outside-focus recovery.

Validation

• npm test -- --runInBand components/ui/ui.test.tsx — passed (17 tests).
• git diff --check and full added-line PolinRider scan — passed.

Closes #458