Username is required: blocking first step on every sign-in until one is saved

showOnboard(required) has no skip and no dismiss; a suggestion from the email
prefix is prefilled (GET /api/my/username-suggest, made unique); the member
area does not render until the username exists. Welcome tour and login ad still
run once for invite arrivals afterwards. Wallet-only sessions are unaffected.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

public/assets/my.js

@@ -523,12 +523,18 @@
     if ($('mcFinish')) $('mcFinish').hidden = !walletOnly;
     if (!signedIn) return;
     if ($('adminLink')) $('adminLink').hidden = !me.isAdmin; // admin portal link, only for ADMIN_EMAIL
-    // arrived from an invite page: run onboarding once (username, welcome tour, login ad)
+    // REQUIRED first step (Marty, 2026-09-12): no username, nothing else. The modal cannot be
+    // skipped or dismissed; it resolves only when a username is saved, then the area renders.
+    if (!me.username) {
+      if (!render.gating) { render.gating = true; showOnboard(true).then(() => { render.gating = false; render(); }); }
+      return;
+    }
+    // arrived from an invite page: run the welcome tour and login ad once
     if (/[?&]welcome=1/.test(location.search) && !render.welcomed) {
       render.welcomed = true;
       history.replaceState(null, '', '/my' + (location.hash || ''));
       (async () => {
-        try { if (!me.username) await showOnboard(); if (!(await showGauntlet())) await showLoginAd(); } catch (e) {}
+        try { if (!(await showGauntlet())) await showLoginAd(); } catch (e) {}
         await render();
       })();
     }
@@ -1771,15 +1777,23 @@
     }));
   })();
 
-  // new-member onboarding: choose a username, optionally a bio (both skippable)
-  function showOnboard() {
+  // new-member onboarding: choose a username (required), optionally a bio.
+  // required=true: no skip, no backdrop dismiss, prefilled suggestion, resolves only after a save.
+  function showOnboard(required) {
     return new Promise(resolve => {
       const m = $('onboardModal'); if (!m) return resolve();
       m.hidden = false; $('obErr').hidden = true;
+      $('obSkip').hidden = !!required;
+      if (required && !$('obUsername').value) {
+        fetch('/api/my/username-suggest').then(r => r.json()).then(r => { if (r.suggest && !$('obUsername').value) { $('obUsername').value = r.suggest; $('obUsername').select(); } }).catch(() => {});
+      }
+      setTimeout(() => $('obUsername').focus(), 50);
       const done = () => { m.hidden = true; resolve(); };
-      $('obSkip').onclick = done;
+      $('obSkip').onclick = required ? null : done;
+      $('obUsername').onkeydown = e => { if (e.key === 'Enter') { e.preventDefault(); $('obSave').click(); } };
       $('obSave').onclick = async () => {
         const u = $('obUsername').value.trim();
+        if (required && !u) { $('obErr').hidden = false; $('obErr').textContent = 'Pick a username to continue.'; return; }
         try {
           if (u) await api('/api/my/profile', { username: u });
           const bio = $('obBio').value.trim();

public/my.html

@@ -98,15 +98,15 @@
 <div id="onboardModal" class="modal-back" hidden>
   <div class="modal-card">
     <p class="eyebrow">Welcome to InstantAdPay</p>
-    <h3 style="margin:.2em 0 .5em">Pick your username</h3>
-    <p class="muted small">This is how your team sees you, and it turns your invite link into a clean vanity link.
-      You can change it later in Profile.</p>
+    <h3 style="margin:.2em 0 .5em">Pick your username to continue</h3>
+    <p class="muted small">This is how your team sees you, and it becomes your invite link and your public page.
+      It is permanent once saved, so pick the one you want to be known by. We suggested one from your email; keep it or change it.</p>
     <p><input id="obUsername" placeholder="Username (3-20 letters, numbers, _)" autocomplete="off" style="width:100%"></p>
     <p class="muted small" style="margin:12px 0 4px">Optional — a short bio for your public page (you can skip this).</p>
     <p><textarea id="obBio" rows="2" maxlength="600" placeholder="A short bio (optional)" style="width:100%"></textarea></p>
     <p id="obErr" class="small" style="color:var(--bad)" hidden></p>
     <p style="margin-top:14px;display:flex;gap:10px;justify-content:flex-end">
-      <button class="btn sec small" id="obSkip" type="button">Skip for now</button>
+      <button class="btn sec small" id="obSkip" type="button" hidden>Skip for now</button>
       <button class="btn" id="obSave" type="button">Save &amp; continue</button>
     </p>
   </div>
@@ -915,7 +915,7 @@
 <script src="/assets/common.js?v=20260912b"></script>
 <script src="/assets/wallet.js?v=20260911a"></script>
 <script src="/assets/promo.js?v=20260911a"></script>
-<script src="/assets/my.js?v=20260912c"></script>
+<script src="/assets/my.js?v=20260912e"></script>
 <script src="/assets/chat.js?v=20260907l"></script>
 </body>
 </html>