refactor: move View Stats and Sign In/Out buttons into DevButtons

Consolidates the dev-only stats and auth buttons into the DevButtons
component, passing user and onSignIn as props. Also comments out the
Twitter link in SocialLinks.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/components/SocialLinks.svelte

@@ -18,7 +18,7 @@
 
 	<div class="w-0.5 h-8 bg-gray-400 dark:bg-gray-600"></div>
 
-	<a
+	<!-- <a
 		href="https://x.com/pupperpowell"
 		target="_blank"
 		rel="noopener noreferrer"
@@ -30,7 +30,7 @@
 		<img src={TwitterLogo} alt="Twitter" class="w-8 h-8" />
 	</a>
 
-	<div class="w-0.5 h-8 bg-gray-400 dark:bg-gray-600"></div>
+	<div class="w-0.5 h-8 bg-gray-400 dark:bg-gray-600"></div> -->
 
 	<a
 		href="mailto:george+bibdle@silentsummit.co"