feat: Implement a 15-minute rate limit per email for contact form submissions.

src/components/Contact.tsx

@@ -27,6 +27,21 @@ const Contact = () => {
 
   const handleSubmit = async (e: React.FormEvent) => {
     e.preventDefault();
+    // Vérification du délai de 15 minutes par email
+    const storageKey = `lastMessageTime_${formData.email}`;
+    const lastMessageTime = localStorage.getItem(storageKey);
+
+    if (lastMessageTime) {
+      const timeSinceLastMessage = Date.now() - parseInt(lastMessageTime, 10);
+      const fifteenMinutes = 15 * 60 * 1000;
+
+      if (timeSinceLastMessage < fifteenMinutes) {
+        const remainingMinutes = Math.ceil((fifteenMinutes - timeSinceLastMessage) / 60000);
+        setError(`Veuillez attendre ${remainingMinutes} minutes avant d'envoyer un nouveau message avec cette adresse email.`);
+        return;
+      }
+    }
+
     setIsSubmitting(true);
     setError(null);
 
@@ -41,6 +56,7 @@ const Contact = () => {
       const result = await sendContactEmail(contactData);
 
       if (result.success) {
+        localStorage.setItem(`lastMessageTime_${formData.email}`, Date.now().toString());
         setIsSubmitted(true);
         setFormData({ name: '', email: '', subject: '', message: '' });