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/clinic/[slug]/loading.js

@@ -1,18 +0,0 @@
-import { Skeleton } from "@mui/material";
-
-export default function Loading() {
-  return (
-    <div className="pt-[40px] sm:pt-[70px] md:pt-[100px] lg:pt-[136px] mt-[40px] padding-responsive">
-      <div className="flex gap-6">
-        <Skeleton variant="rounded" width={100} height={32} />
-        <Skeleton variant="rounded" width={100} height={32} />
-        <Skeleton variant="rounded" width={100} height={32} />
-      </div>
-      <div className="mt-[24px] sm:mt-[27px] md:mt-[30px] lg:mt-[32px] flex flex-col gap-4">
-        <Skeleton variant="rounded" height={200} className="!rounded-lg" />
-        <Skeleton variant="rounded" height={20} className="!w-full" />
-        <Skeleton variant="rounded" height={20} width={300} />
-      </div>
-    </div>
-  );
-}

app/clinic/[slug]/page.js

@@ -4,7 +4,9 @@ import Layout from "@/components/layout/StLayout";
 import { notFound } from "next/navigation";
 import { fetchReq } from "@/lib/req";
 import { getStateInfo } from "@/lib/getStateInfo";
-import { getRequestOrigin } from "@/lib/getCanonicalUrl";
+import { getEntityOrigin } from "@/lib/getCanonicalUrl";
+import { extractEntityCityId } from "@/lib/domainHelpers";
+import { isThinClinic } from "@/lib/entityQuality";
 import { safeJsonLd } from "@/lib/sanitize";
 import { imageUrl } from "@/helper";
 
@@ -38,9 +40,15 @@ export async function generateMetadata({ params }) {
       ? [imageUrl(clinic.images_clinic[0].url)]
       : ["/assets/images/og-image.png"];
 
+    // C1-b — کلینیک به دامنهٔ شهر خودش canonical می‌شود.
+    const origin = await getEntityOrigin(extractEntityCityId(clinic));
+
     return {
       title,
       description,
+      alternates: { canonical: `${origin}/clinic/${clinic.uuid}` },
+      // H7 — کلینیک غیرفعال/بی‌محتوا نباید ایندکس شود (تقارن با پزشک بی‌محتوا)
+      ...(isThinClinic(clinic) && { robots: { index: false, follow: true } }),
       openGraph: {
         title,
         description,
@@ -54,7 +62,8 @@ export async function generateMetadata({ params }) {
         images: image,
       },
     };
-  } catch {
+  } catch (error) {
+    console.error(`[clinic/${slug}] generateMetadata failed:`, error);
     return {};
   }
 }
@@ -74,13 +83,15 @@ function computeClinicRating(doctors) {
 
 async function Clinic({ params, searchParams }) {
   const { slug } = await params;
-  const origin = await getRequestOrigin();
   const sp = await searchParams;
   const page = Number(sp?.page) || 1;
   const limit = 50;
 
   const clinic = await getClinic(slug);
   if (!clinic) notFound();
+
+  // همان مقصد canonical — تا url/@id و breadcrumb سیگنال متناقض ندهند.
+  const origin = await getEntityOrigin(extractEntityCityId(clinic));
   const reqDoctors = await fetchReq(
     `${API_URL}/api/v1/clinic/doctor-list/${slug}?page=${page}&limit=${limit}`
   );
@@ -149,18 +160,6 @@ async function Clinic({ params, searchParams }) {
       }
     : null;
 
-  const breadcrumbJsonLd = clinic
-    ? {
-        "@context": "https://schema.org",
-        "@type": "BreadcrumbList",
-        itemListElement: [
-          { "@type": "ListItem", position: 1, name: "خانه", item: origin },
-          { "@type": "ListItem", position: 2, name: "کلینیک‌ها", item: `${origin}/clinics` },
-          { "@type": "ListItem", position: 3, name: clinic.title },
-        ],
-      }
-    : null;
-
   return (
     <>
       {jsonLd && (
@@ -169,14 +168,15 @@ async function Clinic({ params, searchParams }) {
           dangerouslySetInnerHTML={{ __html: safeJsonLd(jsonLd) }}
         />
       )}
-      {breadcrumbJsonLd && (
-        <script
-          type="application/ld+json"
-          dangerouslySetInnerHTML={{ __html: safeJsonLd(breadcrumbJsonLd) }}
-        />
-      )}
+      {/* BreadcrumbList از خودِ کامپوننت Pageguide می‌آید — یک منبع داده برای بصری و schema */}
       <Layout>
-        <ClinicPage data={clinic} doctors={doctors} slug={slug} pages={pagedoctors} />
+        <ClinicPage
+          data={clinic}
+          doctors={doctors}
+          slug={slug}
+          pages={pagedoctors}
+          origin={origin}
+        />
       </Layout>
     </>
   );