fix: update form action URL for login to include API path

auth/src/templates/loginpage.html

@@ -19,7 +19,7 @@
             <p class="error">{{ error }}</p>
             {% endif %}
 
-            <form action="/login" method="post">
+            <form action="/api/auth/login" method="post">
                 <input type="hidden" name="redirect" value="{{ redirect }}">
                 <div class="group">
                     <label for="username">Username</label>