fix: add missing aria-label on unresolve button

Parity port from crit local: add aria-label="Unresolve thread" to unresolve button.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: tomasz-tomczyk

assets/js/document-renderer.js

@@ -2913,6 +2913,7 @@ function createResolvedElement(comment, ctx) {
   const unresolveBtn = document.createElement('button')
   unresolveBtn.className = 'resolve-btn resolve-btn--active'
   unresolveBtn.title = 'Unresolve'
+  unresolveBtn.setAttribute('aria-label', 'Unresolve thread')
   unresolveBtn.innerHTML = '<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M3 12a9 9 0 0 1 9-9 9 9 0 0 1 6.36 2.64M21 12a9 9 0 0 1-9 9 9 9 0 0 1-6.36-2.64"/><polyline points="21 3 21 8 16 8"/><polyline points="3 21 3 16 8 16"/></svg><span>Unresolve</span>'
   unresolveBtn.addEventListener('click', function() {
     ctx.pushEvent("resolve_comment", { id: comment.id, resolved: false })