Update web/index.html

Display blockchain height in web interface

web/index.html

@@ -185,6 +185,11 @@
           <span class="label">Fulcrum endpoint</span>
           <span id="fulcrum-url" class="value muted">Checking...</span>
         </div>
+
+        <div class="row">
+          <span class="label">Blockchain height</span>
+          <span id="blockchain-height" class="value">Checking...</span>
+        </div>
       </section>
 
       <section class="card">
@@ -303,6 +308,9 @@
         document.getElementById('fulcrum-url').textContent =
           fulcrum.url || 'Not configured';
 
+        document.getElementById('blockchain-height').textContent =
+          fulcrum.blockchainHeight ?? 'Unavailable';
+
         document.getElementById('wallet').textContent =
           status.wallet || 'Not configured';
 
@@ -328,6 +336,7 @@
         );
 
         document.getElementById('fulcrum-url').textContent = 'Unavailable';
+        document.getElementById('blockchain-height').textContent = 'Unavailable';
         errorElement.textContent = 'Unable to retrieve service status.';
       }
     }