@docstack/client 0.3.0: access is a property of the ciphertext
@docstack/client 0.3.0 makes access control cryptographic. Content belongs to a scope whose content key is sealed under an attribute policy, and a session's attribute key either satisfies the formula, opening the scope, or does not, in which case the same ciphertext reads null. Denial is decryption failure, not a check, so it binds the device owner too. The JavaScript-rule policy engine is gone, and a new package, @docstack/abe, carries the primitive.
