Extract initCopyUrl to module, add tests for copy-url and event-map coverage

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

assets/modules/copy-url.js

@@ -0,0 +1,13 @@
+export function initCopyUrl() {
+    const btn = document.getElementById('copy-url-btn')
+    if (!btn) return
+    const url = document.getElementById('event-url')?.textContent?.trim()
+    if (!url) return
+
+    btn.addEventListener('click', () => {
+        globalThis.navigator.clipboard.writeText(url).then(() => {
+            btn.textContent = 'Copie !'
+            setTimeout(() => { btn.textContent = 'Copier le lien' }, 2000)
+        })
+    })
+}