Fixes#2743.
Attach /DefaultCMYK [/ICCBased ...] referencing the CMYK working space profile on every page, inherited /Pages resource dict, Form XObject, SMask form, tiling pattern, and Type3 font resource scope outside PDF/X-1a and PDF/A-2b. Plain print exports and booklets embed one shared Flate-compressed /N 4 ICC profile stream without adding /OutputIntents or /Trapped; PDF/X-4 reuses the catalog GTS_PDFX /DestOutputProfile stream; RGB-blend documents attach /DefaultCMYK only when content or resources use DeviceCMYK.