TW.15 Digital twin: order files from a warehouse system

Built in the lab (Material flow add-on, ModelCraft): a source can take its arrivals from a CSV orders file instead of random times (columns time_s / time_min / time_h / time / clock, type, length_m / length_mm, qty, source, order; the time unit and base are stated in the help). The same file gives the same run for any seed (no random draw is used). A row that cannot be read stops the whole read and the panel names the first bad row (line, column, what the cell said); nothing is skipped. Tables are saved in the model file; Save as CSV writes one back. Sample orders (about 130 invented rows) are in the add-on's data folder and the flow listing's Data section. Tested: lib/flow orders tests in the flow suite, and in the real /lab page (browser-orders.mjs 10/0). Does not read any warehouse system's own format.