feat(#40): Persian (Jalali) date pickers in admin

Add react-multi-date-picker + a reusable PersianDateInput (displays Jalali, stores
Gregorian ISO so DTOs are unchanged). Replace admin date inputs: UserProfileEdit
birthdate + CRM date-range filters.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

package.json

@@ -41,6 +41,7 @@
     "react-dom": "^18",
     "react-hook-form": "^7.76.0",
     "react-konva": "^18.2.16",
+    "react-multi-date-picker": "^4.5.2",
     "react-rnd": "^10.5.3",
     "tailwind-merge": "^3.6.0",
     "use-image": "^1.1.4",