feat: add canonical URL handling and entity quality checks

- Implemented canonical URL strategies for city-specific domains and entities.
- Added helper functions for domain and city resolution.
- Created tests for canonical URL generation and domain resolution.
- Introduced entity quality checks for doctors and clinics to ensure meaningful content.
- Developed unique introductory texts for listing pages to avoid duplicate content.
- Established robots.txt policies for listing pages to manage indexing based on user filters.
- Enhanced specialty content with dynamic introductions and FAQs to improve SEO.

app/component/Pageguide.js

@@ -1,21 +1,72 @@
-function Pageguide({ list }) {
+import Link from "next/link";
+import { safeJsonLd } from "@/lib/sanitize";
+
+// Breadcrumb واحد سایت: ظاهر دقیقاً همان نسخهٔ قبلی (همان کلاس‌ها، همان جداکنندهٔ «>»)
+// ولی ساختار سمانتیک درست (nav/ol/a) و BreadcrumbList از همان یک منبع داده تولید می‌شود
+// تا نسخهٔ بصری و schema هرگز واگرا نشوند.
+//
+// list: Array<string | { name, href }> — آیتم آخر همیشه صفحهٔ جاری است (بدون لینک).
+
+const ITEM_CLASS = "text-[16px] font-normal";
+
+function normalize(list) {
+  return list
+    .map((item) => (typeof item === "string" ? { name: item } : item))
+    .filter((item) => item?.name);
+}
+
+function Pageguide({ list = [], origin }) {
+  const items = normalize(list);
+  if (items.length === 0) return null;
+
+  const jsonLd = {
+    "@context": "https://schema.org",
+    "@type": "BreadcrumbList",
+    itemListElement: items.map((item, idx) => ({
+      "@type": "ListItem",
+      position: idx + 1,
+      name: item.name,
+      ...(item.href && origin && { item: `${origin}${item.href}` }),
+    })),
+  };
+
   return (
-    <ul className="flex items-center justify-start gap-1">
-      {list.map((item, idx) => (
-        <li key={idx} className="flex items-center justify-start gap-1">
-          <h2
-            className={`text-[16px] font-normal ${ list.length > idx + 1 ? "text-[#9B9B9B]" : "text-[#525252]" } `}
-          >
-            {item}
-          </h2>
-          <span
-            className={` text-[#9B9B9B] text-[16px] font-normal ${list.length > idx + 1 ? "flex" : "hidden"} `}
-          >
-            {">"}
-          </span>
-        </li>
-      ))}
-    </ul>
+    <>
+      <script
+        type="application/ld+json"
+        dangerouslySetInnerHTML={{ __html: safeJsonLd(jsonLd) }}
+      />
+      <nav aria-label="breadcrumb">
+        <ol className="flex items-center justify-start gap-1">
+          {items.map((item, idx) => {
+            const isLast = idx === items.length - 1;
+            const colorClass = isLast ? "text-[#525252]" : "text-[#9B9B9B]";
+            return (
+              <li key={idx} className="flex items-center justify-start gap-1">
+                {item.href && !isLast ? (
+                  <Link href={item.href} className={`${ITEM_CLASS} ${colorClass}`}>
+                    {item.name}
+                  </Link>
+                ) : (
+                  <span
+                    className={`${ITEM_CLASS} ${colorClass}`}
+                    {...(isLast && { "aria-current": "page" })}
+                  >
+                    {item.name}
+                  </span>
+                )}
+                <span
+                  className={`text-[#9B9B9B] ${ITEM_CLASS} ${isLast ? "hidden" : "flex"}`}
+                  aria-hidden="true"
+                >
+                  {">"}
+                </span>
+              </li>
+            );
+          })}
+        </ol>
+      </nav>
+    </>
   );
 }