feat: copy full URL from chat header and add native share button (#440)

Agent-Logs-Url: https://github.com/muke1908/chat-e2ee/sessions/aaf031fd-38c1-40b8-93a8-98cdd0751d7f

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: muke1908 <20297989+muke1908@users.noreply.github.com>

Author: Copilot

client/app.ts

@@ -34,6 +34,7 @@ const participantInfo = document.getElementById('participant-info')!;
 const headerHashDisplay = document.getElementById('channel-hash-display')!;
 const headerHashText = document.getElementById('header-hash')!;
 const copyHeaderHashBtn = document.getElementById('copy-header-hash') as HTMLButtonElement;
+const shareBtn = document.getElementById('share-btn') as HTMLButtonElement;
 
 // Call Elements
 const callOverlay = document.getElementById('call-overlay')!;
@@ -132,12 +133,23 @@ copyHashBtn.addEventListener('click', () => {
 });
 
 copyHeaderHashBtn.addEventListener('click', () => {
-    navigator.clipboard.writeText(headerHashText.textContent || '');
+    navigator.clipboard.writeText(window.location.href);
     const originalText = setupStatus.textContent;
-    setupStatus.textContent = 'Hash copied to clipboard!';
+    setupStatus.textContent = 'URL copied to clipboard!';
     setTimeout(() => setupStatus.textContent = originalText, 2000);
 });
 
+if ('share' in navigator) {
+    shareBtn.classList.remove('hidden');
+    shareBtn.addEventListener('click', () => {
+        navigator.share({
+            title: 'Chat E2EE',
+            text: 'Join my end-to-end encrypted chat',
+            url: window.location.href,
+        }).catch(() => { /* user cancelled or share failed */ });
+    });
+}
+
 async function checkExistingUsers() {
     try {
         const users = await chat.getUsersInChannel();

client/index.html

@@ -69,7 +69,7 @@ <h2 id="channel-title">Secure Channel</h2>
                     </div>
                     <div id="channel-hash-display" class="hash-badge-container hidden">
                         <span id="header-hash" class="hash-text"></span>
-                        <button id="copy-header-hash" class="icon-btn tiny" title="Copy Hash">
+                        <button id="copy-header-hash" class="icon-btn tiny" title="Copy Link">
                             <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"
                                 stroke-linecap="round" stroke-linejoin="round">
                                 <rect x="9" y="9" width="13" height="13" rx="2" ry="2"></rect>
@@ -80,6 +80,16 @@ <h2 id="channel-title">Secure Channel</h2>
                     <p id="participant-info">Waiting for someone to join...</p>
                 </div>
                 <div class="header-actions">
+                    <button id="share-btn" title="Share Link" class="icon-btn hidden">
+                        <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"
+                            stroke-linecap="round" stroke-linejoin="round">
+                            <circle cx="18" cy="5" r="3"></circle>
+                            <circle cx="6" cy="12" r="3"></circle>
+                            <circle cx="18" cy="19" r="3"></circle>
+                            <line x1="8.59" y1="13.51" x2="15.42" y2="17.49"></line>
+                            <line x1="15.41" y1="6.51" x2="8.59" y2="10.49"></line>
+                        </svg>
+                    </button>
                     <button id="start-call-btn" title="Start Audio Call" class="icon-btn">
                         <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"
                             stroke-linecap="round" stroke-linejoin="round">