Landing: sign in through the IAP hand-off directly, so PolHunter works standalone

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

public/index.html

@@ -14,7 +14,7 @@
     <nav class="nav">
       <a class="btn ghost sm" href="#how">How it works</a>
       <a class="btn ghost sm" href="#ledger">Paid so far</a>
-      <a class="btn sm" id="signin" href="https://instantadpay.com/my#polhunter">Open my board</a>
+      <a class="btn sm" id="signin" href="https://instantadpay.com/api/my/polhunter">Open my board</a>
     </nav>
   </header>
 
@@ -23,9 +23,9 @@
       <span class="pill"><i></i> Paying in POL on Polygon</span>
       <h1>Visit. Find it.<br><b>Get paid in POL.</b></h1>
       <p>Every mission is a few minutes on one of our sites, one thing to find, and a drip of POL straight to your wallet when you find it. Your code is yours alone, and the hiding place moves.</p>
-      <a class="btn" href="https://instantadpay.com/my#polhunter">Start hunting</a>
+      <a class="btn" href="https://instantadpay.com/api/my/polhunter">Start hunting</a>
       <a class="btn ghost" href="#how" style="margin-left:8px">See how</a>
-      <p id="signinNote" style="font-size:13px;color:var(--dim);margin-top:14px;display:none">Open PolHunter from your InstantAdPay dashboard to sign in. No password, no new account.</p>
+      <p id="signinNote" style="font-size:13px;color:var(--dim);margin-top:14px;display:none">Sign in with your InstantAdPay account: the button sends you through InstantAdPay and straight back here. No password, no new account.</p>
     </div>
     <div class="stack" aria-hidden="true"><div class="c c1"></div><div class="c c2"></div><div class="c c3"></div><div class="g"></div></div>
   </section>