fix: make copy buttons work on HTTP panel pages

Read share links from input fields and fall back to execCommand when
Clipboard API is unavailable outside secure contexts.

Co-authored-by: Cursor <cursoragent@cursor.com>

panel/static/style.css

@@ -70,7 +70,8 @@ body {
 
 input[type="text"],
 input[type="password"],
-input[readonly] {
+input[readonly],
+input.copy-input {
   width: 100%;
   padding: 10px 12px;
   border-radius: 8px;
@@ -79,6 +80,11 @@ input[readonly] {
   color: var(--text);
 }
 
+input.copy-input {
+  cursor: pointer;
+  font-size: 0.82rem;
+}
+
 .btn {
   border: 1px solid var(--border);
   background: #111827;