adaptor sigs are deniable! with a valid bip340sig, anybody can adapt …

…it to an arbitrary point

move PublicKey, PrivateKey and XOnlyPublicKey out of Crypto object.

fix reckless ecc code.

tag v0.5.0

fix CltvExpiry codec such that it doesn't try to reuse BlockHeight.

tag v0.3.0

use tlCrossRootProject.

fix duplicated LastCrossSignedState and publish v0.2.0.

typelevel github workflow.