feat: Implement comprehensive ban enforcement

src/hooks/useAuth.tsx

@@ -110,6 +110,19 @@ function AuthProviderComponent({ children }: { children: React.ReactNode }) {
           const currentAal = await getSessionAal(session);
           setAal(currentAal);
           authLog('[Auth] Current AAL:', currentAal);
+          
+          // Check if user is banned
+          const { data: profile } = await supabase
+            .from('profiles')
+            .select('banned')
+            .eq('user_id', session.user.id)
+            .maybeSingle();
+
+          if (profile?.banned) {
+            authWarn('[Auth] Banned user detected, signing out');
+            await supabase.auth.signOut();
+            return;
+          }
         } else {
           setAal(null);
         }