debug(auth): add visible debug border and user state to AuthPanel

src/components/dm/AuthPanel.astro

@@ -4,6 +4,10 @@ import DmButton from './DmButton.astro';
 const user = Astro.locals.user;
 ---
 
+<!-- DEBUG: user={JSON.stringify(user)} -->
+<div class="border border-dashed border-[var(--accent)] rounded-lg p-2 min-w-[200px]">
+  <div class="text-xs text-[var(--accent)] mb-1 font-mono">AuthPanel: {user ? 'logged-in' : 'logged-out'}</div>
+  
   {!user ? (
     <div class="flex flex-col sm:flex-row gap-3" data-auth-state="logged-out">
       <DmButton
@@ -48,6 +52,7 @@ const user = Astro.locals.user;
       </DmButton>
     </div>
   )}
+</div>
 
 <script>
   (function () {