feat(enclave): add ping function for echoing input messages

example/index.html

@@ -40,6 +40,12 @@
       <button onclick="runAllTests()" style="margin-left: 1rem;">Run All Tests</button>
     </div>
 
+    <div class="card">
+      <h2>ping(message)</h2>
+      <input type="text" id="ping-msg" value="hello from browser" placeholder="Message to echo">
+      <button onclick="testPing()">Run</button>
+    </div>
+
     <div class="card">
       <h2>generate(credential)</h2>
       <input type="text" id="credential" value="dGVzdC1jcmVkZW50aWFs" placeholder="Base64 credential">

example/main.js

@@ -40,6 +40,26 @@ async function init() {
   }
 }
 
+window.testPing = async function() {
+  if (!enclave) return log(LogLevel.ERR, 'ping', 'Plugin not loaded');
+  
+  const message = document.getElementById('ping-msg').value || 'hello';
+  log(LogLevel.INFO, 'ping', `message="${message}"`);
+  
+  try {
+    const result = await enclave.ping(message);
+    if (result.success) {
+      log(LogLevel.OK, 'ping', `echo="${result.echo}"`, result);
+    } else {
+      log(LogLevel.ERR, 'ping', result.message, result);
+    }
+    return result;
+  } catch (err) {
+    log(LogLevel.ERR, 'ping', err?.message || String(err));
+    throw err;
+  }
+};
+
 window.testGenerate = async function() {
   if (!enclave) return log(LogLevel.ERR, 'generate', 'Plugin not loaded');
   
@@ -137,6 +157,7 @@ window.runAllTests = async function() {
   log(LogLevel.INFO, null, '=== Running all tests ===');
   
   try {
+    await testPing();
     await testGenerate();
     await testLoad();
     await testExec();