fix(ux-audit): CRITICAL + HIGH fixes — a11y, reduced-motion, forms, keyboard nav

Global (globals.css):
- prefers-reduced-motion: désactive toutes les animations/transitions
- focus-visible:ring global sur tous les éléments interactifs

Search modal:
- role="dialog" + aria-modal="true" + aria-label
- onClick backdrop ferme la modale

Insights peek:
- DOMPurify.sanitize() sur dangerouslySetInnerHTML (XSS fix)

Login form:
- autoComplete="email" / "current-password"
- htmlFor sur tous les labels

Register form:
- autoComplete="name" / "email" / "new-password"
- htmlFor sur tous les labels

GridCard (notes-list-views):
- Actions visibles sur mobile (opacity-100 sm:opacity-0)
- aria-sort sur colonne triable
- role="button" + tabIndex + onKeyDown sur lignes table

Editorial view:
- role="button" + tabIndex + onKeyDown sur articles
- Menu trigger aria-label + visible mobile

Toolbar:
- aria-label voice i18n

memento-note/components/notes-editorial-view.tsx

@@ -157,7 +157,8 @@ export function EditorialNoteMenu({
         <DropdownMenuTrigger asChild onClick={e => e.stopPropagation()}>
           <button
             ref={menuTriggerRef}
-            className="opacity-0 group-hover:opacity-100 transition-opacity p-1.5 rounded-md hover:bg-muted/60 text-muted-foreground hover:text-foreground"
+            className="opacity-100 sm:opacity-0 sm:group-hover:opacity-100 transition-opacity p-1.5 rounded-md hover:bg-muted/60 text-muted-foreground hover:text-foreground cursor-pointer"
+            aria-label={t('notes.moreOptions') || 'Options'}
           >
             <MoreHorizontal size={15} />
           </button>
@@ -396,6 +397,9 @@ export function NotesEditorialView({
               transition={hydrated ? { delay: 0.05 * index, duration: 0.6 } : { duration: 0 }}
               className="space-y-4 group cursor-pointer relative pb-8"
               onClick={() => onOpen(note)}
+              onKeyDown={(e) => { if (e.key === 'Enter') onOpen(note) }}
+              tabIndex={0}
+              role="button"
             >
               {/* Date / breadcrumb — isolated bidi so Latin notebook name + Jalali date don’t reorder wrongly */}
               <div