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/multiDomainClient.test.js

@@ -1,6 +1,6 @@
-import { describe, it, expect, beforeEach } from 'vitest';
+import { describe, it, expect } from 'vitest';
 import { getStateInfoClient } from '@/lib/getStateInfoClient';
-import { getCanonicalUrlClient } from '@/lib/getCanonicalUrl';
+import { buildCanonicalUrl, buildCanonicalPath, normalizeHost } from '@/lib/getCanonicalUrl';
 
 function setLocation(loc) {
     Object.defineProperty(window, 'location', { value: loc, writable: true, configurable: true });
@@ -21,22 +21,38 @@ describe('getStateInfoClient (window)', () => {
     });
 });
 
-describe('getCanonicalUrlClient (window)', () => {
-    beforeEach(() => {
-        setLocation({ host: 'arak-nobat.ir', pathname: '/doctors' });
+describe('buildCanonicalUrl (self-canonical per-host)', () => {
+    it('دامنه‌ی شهری → self-canonical روی همان دامنه', () => {
+        expect(buildCanonicalUrl('arak-nobat.ir', '/doctors')).toBe('https://arak-nobat.ir/doctors');
     });
 
-    it('subdomain → canonical به دامنه‌ی اصلی', () => {
-        expect(getCanonicalUrlClient()).toBe('https://nobat724.com/doctors');
+    it('دامنه‌ی اصلی → self-canonical روی دامنه‌ی اصلی', () => {
+        expect(buildCanonicalUrl('nobat724.com', '/doctors')).toBe('https://nobat724.com/doctors');
     });
 
-    it('دامنه‌ی اصلی → null', () => {
-        setLocation({ host: 'nobat724.com', pathname: '/doctors' });
-        expect(getCanonicalUrlClient()).toBeNull();
+    it('www و حروف بزرگ نرمال می‌شوند', () => {
+        expect(buildCanonicalUrl('WWW.Nobat724.com', '/x')).toBe('https://nobat724.com/x');
     });
 
-    it('www و حروف بزرگ نرمال می‌شوند (دامنه‌ی اصلی) → null', () => {
-        setLocation({ host: 'WWW.Nobat724.com', pathname: '/x' });
-        expect(getCanonicalUrlClient()).toBeNull();
+    it('هاست dev با پورت → http و حفظ پورت', () => {
+        expect(buildCanonicalUrl('yazd-nobat.localhost:3000', '/doctors')).toBe(
+            'http://yazd-nobat.localhost:3000/doctors'
+        );
+    });
+
+    it('query string و trailing slash حذف می‌شوند', () => {
+        expect(buildCanonicalUrl('arak-nobat.ir', '/doctors/?specialty=قلب')).toBe(
+            'https://arak-nobat.ir/doctors'
+        );
+    });
+
+    it('ریشه دست‌نخورده می‌ماند', () => {
+        expect(buildCanonicalUrl('arak-nobat.ir', '/')).toBe('https://arak-nobat.ir/');
+        expect(buildCanonicalPath('/')).toBe('/');
+    });
+
+    it('هاست خالی → دامنه‌ی پیش‌فرض', () => {
+        expect(normalizeHost('')).toBe('nobat724.com');
+        expect(buildCanonicalUrl(null, '/x')).toBe('https://nobat724.com/x');
     });
 });