Fix sidebar header to show logo + brand name inline, improve favicon update logic

- Update AppLayout to display logo and brand name together in all headers (sidebar, public, mobile)
- Improve favicon update in useBranding to create link element if not exists
- Update opengraph metadata to use local image instead of lovable.dev URL
- Change author/meta to WithDwindi branding

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/hooks/useBranding.tsx

@@ -93,8 +93,13 @@ export function BrandingProvider({ children }: { children: ReactNode }) {
 
       // Update favicon if set
       if (data.brand_favicon_url) {
-        const link = document.querySelector("link[rel~='icon']") as HTMLLinkElement;
-        if (link) link.href = data.brand_favicon_url;
+        let link = document.querySelector("link[rel~='icon']") as HTMLLinkElement;
+        if (!link) {
+          link = document.createElement('link');
+          link.rel = 'icon';
+          document.head.appendChild(link);
+        }
+        link.href = data.brand_favicon_url;
       }
 
       // Update document title