feat(metadata): enhance SEO by adding Open Graph and Twitter metadata across various pages

feat(blog): implement loading and error handling components for blog pages

feat(clinic): add loading and error handling components for clinic pages

feat(doctor): create loading and error handling components for doctor pages

feat(clinics): add loading component for clinics page

feat(specialties): improve metadata for specialties page with Open Graph and Twitter images

feat(layout): add structured data for Organization and WebSite in layout

fix(middleware): restrict middleware execution to specific routes to improve performance

chore(audit): add comprehensive SEO and performance audit documentation

app/error.js

@@ -0,0 +1,19 @@
+"use client";
+
+export default function Error({ error, reset }) {
+  return (
+    <div
+      className="flex flex-col items-center justify-center gap-4 min-h-[60vh] p-8 text-center"
+      dir="rtl"
+    >
+      <p className="text-[#3B3B3B] text-[16px] font-bold">مشکلی پیش آمد.</p>
+      <p className="text-[#616161] text-[14px]">لطفاً دوباره تلاش کنید.</p>
+      <button
+        onClick={() => reset()}
+        className="px-6 py-2 rounded-full bg-[#3B3B3B] text-white text-[14px] font-medium"
+      >
+        تلاش دوباره
+      </button>
+    </div>
+  );
+}