Add sidebarActive check to accessibility page

Prevents sidebar nav from interfering with content nav on
the accessibility page.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

kjvstudy_org/templates/accessibility.html

@@ -564,6 +564,8 @@
         if (e.target.tagName === 'INPUT' || e.target.tagName === 'TEXTAREA' || e.target.tagName === 'SELECT') {
             return;
         }
+        // Don't handle if sidebar navigation is active
+        if (KJVNav.sidebarActive) return;
 
         if (e.key === 'j' || e.key === 'ArrowDown') {
             e.preventDefault();