[Accessibility] uabb-separator — empty div instead of semantic hr

[ShubhamGupta05]

Parent: #238

Findings (0 P0, 1 P1, 0 P2, 0 P3 = 1 total)

P1 Major:

1. frontend.php:12-14 — Empty <div> styled with border-top instead of semantic <hr> element. Screen readers have no indication that a content section boundary exists (WCAG 1.3.1)

Files

• modules/uabb-separator/includes/frontend.php
• modules/uabb-separator/includes/frontend.css.php (update selector to target hr)