Add "on Mew" to CTA copy for branding

- Updated CTA text to "Follow accounts you care about on Mew"
- Reinforces brand identity in the call-to-action

Co-authored-by: shakespeare.diy <assistant@shakespeare.diy>

src/components/Feed.tsx

@@ -44,7 +44,7 @@ export function Feed() {
         <div className="border-b border-border sticky top-10 sidebar:top-0 bg-gradient-to-r from-primary/5 via-primary/10 to-primary/5 backdrop-blur-md z-10 py-3">
           <div className="flex items-center justify-center gap-3 px-6">
             <p className="text-sm text-muted-foreground">
-              Follow accounts you care about
+              Follow accounts you care about on Mew
             </p>
             <Button
               onClick={() => setLoginDialogOpen(true)}