As an admin, I want to use and edit custom fields when creating offer letters, so that I can personalize and preview the documents efficiently without switching screens, reducing errors and saving time.
GIVEN I am creating an offer letter in the hiring module
WHEN I select or draft a template for the offer letter
THEN a modal popup should allow me to:
Directly edit the letter's content, including placeholders for custom and system fields.
Preview the letter in real time as I make changes.
AND I should have access to all custom fields created in the system to insert them dynamically into the offer letter.
AND the system should validate placeholders to prevent errors before sending the letter to the applicant.