feat(security): enforce input length limits in contact form

- Added `EMAIL_MAX_LENGTH` constant (254).
- Added `maxLength` attributes to Name, Email, Subject, and Message inputs.
- Updated `validateForm` to check email length.
- Mitigates client-side DoS and improves UX.

Co-authored-by: ragusa-it <196988693+ragusa-it@users.noreply.github.com>

src/pages/Contact.tsx

@@ -9,6 +9,7 @@ import { sanitizeInput, isValidEmail } from "../utils/security";
 import styles from "./Contact.module.css";
 
 const NAME_MAX_LENGTH = 100;
+const EMAIL_MAX_LENGTH = 254;
 const SUBJECT_MAX_LENGTH = 200;
 const MESSAGE_MAX_LENGTH = 5000;
 
@@ -53,6 +54,8 @@ export function Contact() {
 
     if (!formData.email.trim()) {
       newErrors.email = "Required";
+    } else if (formData.email.length > EMAIL_MAX_LENGTH) {
+      newErrors.email = `Max ${EMAIL_MAX_LENGTH} characters`;
     } else if (!isValidEmail(formData.email)) {
       newErrors.email = "Invalid email";
     }
@@ -165,6 +168,7 @@ export function Contact() {
                   value={formData.name}
                   onChange={(e) => handleChange("name", e.target.value)}
                   error={errors.name}
+                  maxLength={NAME_MAX_LENGTH}
                 />
 
                 <Input
@@ -174,6 +178,7 @@ export function Contact() {
                   value={formData.email}
                   onChange={(e) => handleChange("email", e.target.value)}
                   error={errors.email}
+                  maxLength={EMAIL_MAX_LENGTH}
                 />
 
                 <Input
@@ -182,6 +187,7 @@ export function Contact() {
                   value={formData.subject}
                   onChange={(e) => handleChange("subject", e.target.value)}
                   error={errors.subject}
+                  maxLength={SUBJECT_MAX_LENGTH}
                 />
 
                 <Textarea
@@ -191,6 +197,7 @@ export function Contact() {
                   onChange={(e) => handleChange("message", e.target.value)}
                   error={errors.message}
                   rows={6}
+                  maxLength={MESSAGE_MAX_LENGTH}
                 />
 
                 <Button