Omit email digest UI if env variable is not set.

src/routes/settings/alerts/+page.svelte

@@ -17,6 +17,7 @@
   import {Mail} from "@app/mail"
   import {notificationSettings, publishSettings, userSettingsValues} from "@app/settings"
   import {emailNotificationState} from "@app/push/adapters/common"
+  import {EMAIL_NOTIFICATION_SERVER} from "@app/env"
 
   const clearError = () => {
     if ($emailNotificationState.error) {
@@ -185,6 +186,7 @@
         {/snippet}
       </FieldInline>
     </div>
+    {#if EMAIL_NOTIFICATION_SERVER}
       <div class="card bg-surface flex flex-col gap-4 shadow-md">
         <strong class="text-lg">Email Digest Settings</strong>
         <FieldInline>
@@ -230,6 +232,7 @@
           </div>
         {/if}
       </div>
+    {/if}
     <div class="card sticky -bottom-3 shadow-md flex flex-row items-center justify-between gap-4">
       <Button class="button button-neutral" onclick={reset} disabled={loading}
         >Discard Changes</Button>