[ADE-137] - Update auth error messages for clarity and improve email validation prompt

Author: jkestering-modus

frontend/src/common/utils/auth-errors.ts

@@ -5,13 +5,13 @@ import { AuthError } from '../models/auth';
  */
 export const AUTH_ERROR_MESSAGES: Record<string, string> = {
   // Sign In errors
-  'UserNotFoundException': 'The email address or password you entered is incorrect.',
-  'NotAuthorizedException': 'The email address or password you entered is incorrect.',
+  'UserNotFoundException': 'Incorrect email or password.',
+  'NotAuthorizedException': 'Incorrect email or password.',
   'UserNotConfirmedException': 'Please check your email to verify your account.',
   'PasswordResetRequiredException': 'You need to reset your password. Please check your email.',
 
   // Sign Up errors
-  'UsernameExistsException': 'This email address is already associated with an account. Please sign in or reset your password.',
+  'UsernameExistsException': 'This email is already linked to an account. Please sign in or reset your password.',
   'InvalidPasswordException': 'Password does not meet the requirements. Please use a stronger password.',
   'InvalidParameterException': 'Please check your input and try again.',
 

frontend/src/common/utils/i18n/resources/en/auth.json

@@ -70,7 +70,7 @@
     "numeric": "Must contain only numbers",
     "exact-length": "Must be exactly {{length}} characters",
     "passwords-match": "Passwords must match",
-    "email": "Please enter a valid email address",
+    "email": "Please provide a valid email address (e.g., [email protected]).",
     "required": "This field is required",
     "min-length": "Must be at least {{length}} characters",
     "max-length": "Must be at most {{length}} characters",