InteractiveClamps.MaterialInKeepOut flattened a sub-tolerance keep-out with
the 0.001 polygon tolerance and called a part covering a 1e-5 clamp clear,
so the fill safety net could pass it. Keep-outs below the tolerance now use
KeepOutOverlap. Adds the 1e-5 zone sweep through every fill strategy and a
push (characterization; both already stay clear).
PM b0062c73-40ef-440e-8efb-b94908f7c2d1