no registering option

src/lib/Navbar.svelte

@@ -10,6 +10,8 @@
   $: myDecksActive = loc === '/' || loc === '/decks/new' || /^\/decks\/[^/]+\/edit$/.test(loc) || $navContext === 'my-decks';
   $: communityActive = loc === '/community' || loc.startsWith('/community/') || $navContext === 'community';
 
+  const registrationDisabled = import.meta.env.VITE_DISABLE_REGISTRATION === 'true';
+
   let showPopup = false;
   let mode = 'login'; // 'login' | 'register'
   let email = '';
@@ -206,14 +208,16 @@
         >
           Log in
         </button>
-        <button
-          type="button"
-          class="tab"
-          class:active={mode === 'register'}
-          onclick={() => { mode = 'register'; auth.clearError(); registerSuccess = false; }}
-        >
-          Register
-        </button>
+        {#if !registrationDisabled}
+          <button
+            type="button"
+            class="tab"
+            class:active={mode === 'register'}
+            onclick={() => { mode = 'register'; auth.clearError(); registerSuccess = false; }}
+          >
+            Register
+          </button>
+        {/if}
       </div>
 
       {#if registerSuccess && !$auth.user}
@@ -250,7 +254,7 @@
           />
           {#if $auth.error}
             <p class="auth-error">{$auth.error}</p>
-            {#if mode === 'login'}
+            {#if mode === 'login' && !registrationDisabled}
               <p class="auth-switch">
                 Do you have an account? <button type="button" class="auth-link" onclick={() => { mode = 'register'; auth.clearError(); }}>Register here</button>.
               </p>