It was a productive Friday and I have great news!

- I fixed the mining bug so all constructs will now be valid.

- noble/hashes/sha256 is not broken; it was my mistake 😋

- you can now clear out old mined-but-unpublished constructs with the click of a button

- the default mining target is now the center of Ideaspace. I've annotated the code with an explanation of how I determined the center coordinate. You can change your target to the center of Dataspace by changing the final F to an E.