Create problem request

Internal-only override for the persisted plain-text rendering of the description. When non-empty, AbstractRequestService persists it as RequestDetail.description instead of running HTMLSanitizerUtil.getPlainText() on the HTML description. Set ONLY by the email ingestion path (EmailIntentBasedRequestCreationService), which derives it from reqDescription via normalizeHtmlToPlainText(getPlainTextForRichHtml(...)) so system-generated HTML emails (BlackLine offboarding, etc.) avoid mashed table cells and blank-line storms. Annotated @JsonIgnore so external HTTP clients cannot set it via the request body — without that annotation, any caller of POST /requests, /service-requests, /incidents could write arbitrary unsanitized text into RequestDetail.description, bypassing the getPlainText() pipeline. The Lombok @SuperBuilder still exposes a setter for in-process Java callers (the email path), since builder access does not go through Jackson.