Add public events page, event detail route, copy URL button, organizer events list

- Add /evenements public page with Meilisearch search, KnpPaginator (12/page), event cards grid
- Add /evenement/{orgaSlug}/{id}-{eventSlug} public route with slug redirect
- Add Event::getSlug() method
- Update homepage stats with real event count
- Update organizer detail page to list their public events
- Update navbar: link Evenements to /evenements with active state
- Add copy URL button on edit event page (visible only when online)
- Add initCopyUrl() in app.js with clipboard API

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

assets/app.js

@@ -4,9 +4,24 @@ import { initTabs } from "./modules/tabs.js"
 import { registerEditor } from "./modules/editor.js"
 import { initCookieConsent } from "./modules/cookie-consent.js"
 
+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)
+        })
+    })
+}
+
 document.addEventListener('DOMContentLoaded', () => {
     initMobileMenu()
     initTabs()
     registerEditor()
     initCookieConsent()
+    initCopyUrl()
 })