Implement multi-domain SEO improvements:

- Add metadata to login and login-verify pages to prevent indexing.
- Update robots.txt to disallow additional sensitive paths.
- Enhance sitemap generation to filter by city and include accurate last modified dates.
- Refactor canonical URL generation to support multi-domain architecture, ensuring self-canonicalization for city domains.
- Remove deprecated CanonicalHandler component and streamline canonical URL handling.
- Introduce safe JSON-LD output to prevent XSS vulnerabilities.
- Add payment layout with appropriate metadata to prevent indexing.
- Conduct a comprehensive technical SEO audit and implement necessary fixes across the application.

lib/getCanonicalUrl.js

@@ -1,80 +1,50 @@
 import { headers } from "next/headers";
-import citiesData from "@/data/city.json";
 
-const MAIN_DOMAIN = "https://nobat724.com";
+// استراتژی چند-دامنه‌ای: هر دامنه‌ی شهری یک property مستقل و first-class است.
+// هر صفحه self-canonical روی هاست جاری می‌گیرد؛ هرگز به دامنه‌ی اصلی canonical نمی‌دهیم.
+
+const DEFAULT_HOST = "nobat724.com";
+
+export function normalizeHost(rawHost) {
+    return (rawHost || DEFAULT_HOST).toLowerCase().replace(/^www\./, "");
+}
+
+export function buildCanonicalPath(pathname) {
+    let path = (pathname || "/").split("?")[0].split("#")[0];
+    if (!path.startsWith("/")) path = `/${path}`;
+    if (path.length > 1 && path.endsWith("/")) path = path.slice(0, -1);
+    return path;
+}
+
+export function buildCanonicalUrl(host, pathname) {
+    const normalizedHost = normalizeHost(host);
+    const hostname = normalizedHost.replace(/:\d+$/, "");
+    const protocol =
+        hostname.endsWith("localhost") || hostname === "127.0.0.1" ? "http" : "https";
+    return `${protocol}://${normalizedHost}${buildCanonicalPath(pathname)}`;
+}
+
+// origin هاست جاری (بدون trailing slash) — برای ساخت URLهای مطلق در JSON-LD و متادیتا
+export async function getRequestOrigin() {
+    try {
+        const headersList = await headers();
+        return buildCanonicalUrl(headersList.get("host"), "/").replace(/\/$/, "");
+    } catch {
+        return "https://nobat724.com";
+    }
+}
 
-/**
- * Determines if the current domain should have a canonical tag
- * and returns the canonical URL if needed
- */
 export async function getCanonicalUrl() {
     try {
         const headersList = await headers();
-        const host = headersList.get("host") || "";
-        const pathname = headersList.get("x-pathname") || "/";
-
-        // Normalize host (remove www and convert to lowercase)
-        const normalizedHost = host.toLowerCase().replace(/^www\./, "");
-
-        // Check if current domain is the main domain
-        if (normalizedHost === "nobat724.com") {
-            return null; // No canonical needed for main domain
-        }
-
-        // Check if this is a subdomain/different domain from our city data
-        const subdomain = normalizedHost.split(".")[0];
-        const matchedCity = citiesData.find((city) => {
-            const cityDomain = city.domain.toLowerCase();
-            return cityDomain.includes(subdomain) || cityDomain === normalizedHost;
-        });
-
-        // If we found a matching city or any non-main domain, canonicalize to main domain
-        if (matchedCity || normalizedHost !== "nobat724.com") {
-            // Ensure pathname starts with /
-            const cleanPathname = pathname.startsWith("/") ? pathname : `/${pathname}`;
-            return `${MAIN_DOMAIN}${cleanPathname}`;
-        }
-
-        return null;
+        const host = headersList.get("host");
+        const pathname = headersList.get("x-pathname");
+        // مسیرهای خارج از matcher میدل‌ور (panel/dashboard/login) این هدر را ندارند —
+        // آن‌ها noindex هستند و نباید canonical جعلی به ریشه بگیرند.
+        if (!pathname) return null;
+        return buildCanonicalUrl(host, pathname);
     } catch (error) {
         console.error("Error generating canonical URL:", error);
         return null;
     }
 }
-
-/**
- * Client-side version for dynamic routes or client components
- */
-export function getCanonicalUrlClient() {
-    if (typeof window === "undefined") return null;
-
-    try {
-        const host = window.location.host;
-        const pathname = window.location.pathname;
-
-        // Normalize host (remove www and convert to lowercase)
-        const normalizedHost = host.toLowerCase().replace(/^www\./, "");
-
-        // Check if current domain is the main domain
-        if (normalizedHost === "nobat724.com") {
-            return null; // No canonical needed for main domain
-        }
-
-        // Check if this is a subdomain/different domain from our city data
-        const subdomain = normalizedHost.split(".")[0];
-        const matchedCity = citiesData.find((city) => {
-            const cityDomain = city.domain.toLowerCase();
-            return cityDomain.includes(subdomain) || cityDomain === normalizedHost;
-        });
-
-        // If we found a matching city or any non-main domain, canonicalize to main domain
-        if (matchedCity || normalizedHost !== "nobat724.com") {
-            return `${MAIN_DOMAIN}${pathname}`;
-        }
-
-        return null;
-    } catch (error) {
-        console.error("Error generating client canonical URL:", error);
-        return null;
-    }
-}