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/doctors/head/FilterLocate.js

@@ -20,12 +20,13 @@ function FilterLocate({ filter, sendReq, setFilter, setDataInURL }) {
         onClick={() => setOpen(true)}
       >
         <LocationD />
-        <h1 className="text-[#525252] text-[16px] font-semibold">
+        {/* متن دکمهٔ انتخاب موقعیت، عنوان صفحه نیست — تگ عوض شد، کلاس‌ها دست‌نخورده */}
+        <span className="text-[#525252] text-[16px] font-semibold">
           {" "}
           {filter?.state?.name || "استان"}
           {" / "}
           {filter?.city?.name || "شهر"}
-        </h1>
+        </span>
       </Button>
     </ModalSearchCity>
   );