feat: dynamic website title from branding settings

Update document title based on company name and tagline settings:
- Both filled: "{Company Name} - {Tagline}"
- Name only: "{Company Name}"
- Neither: "PicPeak - Photo Sharing Platform" (default)

frontend/src/components/common/DynamicFavicon.tsx

@@ -2,6 +2,8 @@ import { useEffect } from 'react';
 import { useQuery } from '@tanstack/react-query';
 import { getApiBaseUrl, buildResourceUrl } from '../../utils/url';
 
+const DEFAULT_TITLE = 'PicPeak - Photo Sharing Platform';
+
 export const DynamicFavicon: React.FC = () => {
   const { data: settings } = useQuery({
     queryKey: ['public-settings'],
@@ -19,6 +21,7 @@ export const DynamicFavicon: React.FC = () => {
     staleTime: 5 * 60 * 1000, // 5 minutes
   });
 
+  // Update favicon when branding settings change
   useEffect(() => {
     if (settings?.branding_favicon_url) {
       // Remove existing favicon links
@@ -29,13 +32,27 @@ export const DynamicFavicon: React.FC = () => {
       const link = document.createElement('link');
       link.rel = 'icon';
       link.type = 'image/png';
-      link.href = settings.branding_favicon_url.startsWith('http') 
+      link.href = settings.branding_favicon_url.startsWith('http')
-        ? settings.branding_favicon_url 
+        ? settings.branding_favicon_url
         : buildResourceUrl(settings.branding_favicon_url);
-      
+
       document.head.appendChild(link);
     }
   }, [settings?.branding_favicon_url]);
 
+  // Update document title when company name or tagline changes
+  useEffect(() => {
+    const companyName = settings?.branding_company_name?.trim();
+    const tagline = settings?.branding_company_tagline?.trim();
+
+    if (companyName && tagline) {
+      document.title = `${companyName} - ${tagline}`;
+    } else if (companyName) {
+      document.title = companyName;
+    } else {
+      document.title = DEFAULT_TITLE;
+    }
+  }, [settings?.branding_company_name, settings?.branding_company_tagline]);
+
   return null;
 };