fix: use functional state updater in validateInput to prevent stale closure

validateInput was directly mutating the formErrors state object and
then spreading it. When handleSubmit called validateInput twice in
succession, the second call operated on stale closure values because
React batches state updates. Also fixed handleOnFocus for the same
issue.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/reset-password/ResetPasswordPage.jsx

@@ -93,28 +93,27 @@ const ResetPasswordPageInner = () => {
   };
 
   const validateInput = (name, value) => {
+    let fieldError = '';
     switch (name) {
       case 'newPassword':
         if (!value || !LETTER_REGEX.test(value) || !NUMBER_REGEX.test(value) || value.length < 8) {
-          formErrors.newPassword = formatMessage(messages['password.validation.message']);
+          fieldError = formatMessage(messages['password.validation.message']);
         } else {
           validatePasswordFromBackend(value);
         }
         break;
       case 'confirmPassword':
         if (!value) {
-          formErrors.confirmPassword = formatMessage(messages['confirm.your.password']);
+          fieldError = formatMessage(messages['confirm.your.password']);
         } else if (value !== newPassword) {
-          formErrors.confirmPassword = formatMessage(messages['passwords.do.not.match']);
-        } else {
-          formErrors.confirmPassword = '';
+          fieldError = formatMessage(messages['passwords.do.not.match']);
         }
         break;
       default:
         break;
     }
-    setFormErrors({ ...formErrors });
-    return !Object.values(formErrors).some(x => (x !== ''));
+    setFormErrors((prev) => ({ ...prev, [name]: fieldError }));
+    return !fieldError;
   };
 
   const handleOnBlur = (event) => {
@@ -130,7 +129,7 @@ const ResetPasswordPageInner = () => {
   };
 
   const handleOnFocus = (e) => {
-    setFormErrors({ ...formErrors, [e.target.name]: '' });
+    setFormErrors((prev) => ({ ...prev, [e.target.name]: '' }));
   };
 
   const handleSubmit = (e) => {