Various pre-launch fixes.

app/components/SignupFlowOverlay.vue

@@ -33,8 +33,7 @@
             </dl>
           </DashedBox>
           <p class="signup-flow-body" style="margin-top: 16px">
-            Check {{ summary?.email }} for a sign-in link to finish setting up
-            your account. The link expires in 15 minutes.
+            {{ successMessage || `Check ${summary?.email} for a sign-in link to finish setting up your account. The link expires in 15 minutes.` }}
           </p>
         </template>
 
@@ -62,6 +61,7 @@ const props = defineProps({
   summary: { type: Object, default: null },
   errorMessage: { type: String, default: "" },
   dashboardHref: { type: String, default: "/welcome" },
+  successMessage: { type: String, default: "" },
 });
 
 defineEmits(["close"]);