feat(admin): enhance editor UI (links, image captions) & fix categories

Added animated auto-opening link modal, custom image node with isolated caption deletion, fixed single-select category data binding, improved featured image layout, and updated README.

frontend/src/pages/ArticleDetail.tsx

@@ -82,6 +82,7 @@ export function ArticleDetail() {
         <img
           src={article.image}
           alt={article.image_alt || article.title}
+          title={article.image_title || undefined}
           className="absolute inset-0 h-full w-full object-cover"
         />
         <div className="absolute inset-0 bg-ink/75" aria-hidden="true" />

frontend/src/pages/Blog.tsx

@@ -9,6 +9,7 @@ import { useSite } from '../api'
 import { EditableItem } from '../admin/Editable'
 import { useAdmin } from '../admin/AdminContext'
 import { formatJalali } from '../utils/date'
+import { toPersianDigits } from '../utils/digits'
 import { PlusIcon } from 'lucide-react'
 
 function DraftBadge({ className = '' }: { className?: string }) {
@@ -95,7 +96,7 @@ export function Blog() {
                     <span>{formatJalali(featured.date)}</span>
                     <span className="flex items-center gap-1.5">
                       <ClockIcon className="h-3.5 w-3.5" />
-                      {featured.read}
+                      {toPersianDigits(featured.read)}
                     </span>
                   </span>
                   <span className="flex items-center gap-2 text-copper">