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.

components/blog/head/index.js

@@ -1,7 +1,7 @@
 import Link from "next/link";
 import { convertTimestampToJalali } from "@/helper";
 
-function Head({ data }) {
+function Head({ data, cityName }) {
   const firstTag = data?.tag?.[0];
   const createdDate = data?.created ? convertTimestampToJalali(data.created) : "";
 
@@ -34,6 +34,18 @@ function Head({ data }) {
         </h1>
       </div>
       <div className="flex mt-[16px] sm:mt-[18px] md:mt-[21px] lg:mt-[24px] items-center justify-start gap-[35px]">
+        {/* شهر پست در HTML قابل‌مشاهده — نه فقط در متادیتا. برچسب با همان
+            تایپوگرافی «نویسنده/تاریخ» تا با بقیهٔ سربرگ هم‌خانواده بماند. */}
+        {cityName && (
+          <div className="flex items-center justify-start gap-1">
+            <p className="text-[#9B9B9B] text-[11px] md:text-[13px] lg:text-[14px] font-normal">
+              مخصوص شهر:
+            </p>
+            <p className="text-[#9B9B9B] text-[11px] md:text-[14px] lg:text-[16px] font-medium">
+              {cityName}
+            </p>
+          </div>
+        )}
         {data?.author && (
           <div className="flex items-center justify-start gap-1">
             <p className="text-[#9B9B9B] text-[11px] md:text-[13px] lg:text-[14px] font-normal">