chore: update project branding from SaaS-PDF to Dociva

- Updated robots.txt to reflect new site name and sitemap URL.
- Modified sitemap.xml to change all URLs from saas-pdf.com to dociva.io.
- Changed storage key for site assistant in SiteAssistant.tsx.
- Updated SEOHead.tsx to change site name in meta tags.
- Translated app name and related text in Arabic, English, and French JSON files.
- Updated contact email in ContactPage.tsx, PrivacyPage.tsx, and TermsPage.tsx.
- Changed internal admin page title to reflect new branding.
- Updated pricing page meta description to reference Dociva.
- Adjusted Nginx configuration for new domain.
- Modified deployment script to reflect new branding.
- Updated sitemap generation script to use new domain.

frontend/public/robots.txt

@@ -1,4 +1,4 @@
-# robots.txt — SaaS-PDF
+# robots.txt — Dociva
 User-agent: *
 Allow: /
 Disallow: /api/
@@ -7,7 +7,7 @@ Disallow: /forgot-password
 Disallow: /reset-password
 
 # Sitemaps
-Sitemap: https://saas-pdf.com/sitemap.xml
+Sitemap: https://dociva.io/sitemap.xml
 
 # AI/LLM discoverability
 # See also: /llms.txt