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/utils/digits.ts

@@ -0,0 +1,6 @@
+const PERSIAN_DIGITS = '۰۱۲۳۴۵۶۷۸۹'
+
+/** تبدیل ارقام لاتین به ارقام فارسی — برای نمایش یکدست فارسی */
+export function toPersianDigits(value: string | number): string {
+  return String(value).replace(/[0-9]/g, (digit) => PERSIAN_DIGITS[Number(digit)])
+}