Fix Google Form Grid parser, survey display, and instant copy link button

js/teacher.js

@@ -385,9 +385,9 @@ async function teacherGenerateLink(id) {
             <div class="qr-link-container">
                 <div class="qr-link-section">
                     <div class="qr-link-label">🔗 ลิงก์แบบสอบถาม</div>
-                    <div class="link-display">
-                        <span class="flex-1" id="surveyLinkText">${fullUrl}</span>
-                        <button class="copy-btn" onclick="copyTeacherLink()">📋 คัดลอก</button>
+                    <div class="link-display" onclick="copyTeacherLink(this.querySelector('.copy-btn'))" style="cursor:pointer;" title="คลิกเพื่อคัดลอกลิงก์">
+                        <span class="flex-1 select-all" id="surveyLinkText">${fullUrl}</span>
+                        <button class="copy-btn" onclick="event.stopPropagation(); copyTeacherLink(this)">📋 คัดลอก</button>
                     </div>
                 </div>
                 <div class="qr-code-section">
@@ -425,13 +425,11 @@ async function teacherGenerateLink(id) {
     }
 }
 
-function copyTeacherLink() {
-    const text = document.getElementById('surveyLinkText')?.textContent;
+function copyTeacherLink(btnEl) {
+    const text = document.getElementById('surveyLinkText')?.textContent?.trim();
     if (text) {
-        navigator.clipboard.writeText(text).then(() => Toast.success('คัดลอกแล้ว')).catch(() => {
-            const ta = document.createElement('textarea'); ta.value = text; document.body.appendChild(ta); ta.select(); document.execCommand('copy'); ta.remove();
-            Toast.success('คัดลอกแล้ว');
-        });
+        const btn = btnEl || document.querySelector('.link-display .copy-btn');
+        copyTextToClipboard(text, btn);
     }
 }