fix: prevent turnstile during prerender

Jenkinsfile

@@ -334,6 +334,13 @@ stage('SonarQube Quality Gate') {
 
             steps {
                 sh '''
+                    set -a
+                    . /opt/furious-ducks/secrets/tiptop-mail.env
+                    set +a
+
+                    test -n "${TURNSTILE_SITE_KEY}"
+                    echo "Turnstile site key chargée (longueur: ${#TURNSTILE_SITE_KEY})"
+
                     docker build \
                       -t "${BACKEND_IMAGE}:${IMAGE_TAG}" \
                       backend

frontend/src/components/Captcha.jsx

@@ -1,5 +1,5 @@
 import { useEffect, useRef } from 'react'
-import { TURNSTILE_SITE_KEY } from '../config/captcha'
+import { CAPTCHA_ENABLED, TURNSTILE_SITE_KEY } from '../config/captcha'
 
 const TURNSTILE_SCRIPT_ID = 'cf-turnstile-script'
 const TURNSTILE_SCRIPT_URL =
@@ -10,7 +10,9 @@ export default function Captcha({ onToken }) {
   const widgetIdRef = useRef(null)
 
   useEffect(() => {
-    if (!TURNSTILE_SITE_KEY || !containerRef.current) return
+    if (!CAPTCHA_ENABLED || !TURNSTILE_SITE_KEY || !containerRef.current) {
+      return
+    }
 
     let cancelled = false
 
@@ -27,7 +29,7 @@ export default function Captcha({ onToken }) {
         try {
           window.turnstile.remove(widgetIdRef.current)
         } catch {
-          // Rien à faire
+          // Widget déjà supprimé
         }
 
         widgetIdRef.current = null
@@ -41,6 +43,7 @@ export default function Captcha({ onToken }) {
           sitekey: TURNSTILE_SITE_KEY,
           language: 'fr',
           size: 'flexible',
+          appearance: 'always',
 
           callback: (token) => {
             onToken(token)
@@ -66,23 +69,28 @@ export default function Captcha({ onToken }) {
       return
     }
 
-    const previousCallback = window.onloadTurnstileCallback
+    if (existingScript) {
+      existingScript.addEventListener('load', renderWidget, {
+        once: true,
+      })
 
-    window.onloadTurnstileCallback = () => {
+      return () => {
-      previousCallback?.()
+        cancelled = true
-      renderWidget()
+      }
     }
 
-    if (!existingScript) {
     const script = document.createElement('script')
 
     script.id = TURNSTILE_SCRIPT_ID
-      script.src = `${TURNSTILE_SCRIPT_URL}&onload=onloadTurnstileCallback`
+    script.src = TURNSTILE_SCRIPT_URL
     script.async = true
     script.defer = true
 
+    script.addEventListener('load', renderWidget, {
+      once: true,
+    })
+
     document.head.appendChild(script)
-    }
 
     return () => {
       cancelled = true
@@ -94,7 +102,7 @@ export default function Captcha({ onToken }) {
         try {
           window.turnstile.remove(widgetIdRef.current)
         } catch {
-          // Rien à faire
+          // Widget déjà supprimé
         }
       }
 
@@ -102,7 +110,9 @@ export default function Captcha({ onToken }) {
     }
   }, [onToken])
 
-  if (!TURNSTILE_SITE_KEY) return null
+  if (!CAPTCHA_ENABLED || !TURNSTILE_SITE_KEY) {
+    return null
+  }
 
   return (
     <div