The long-term key was derived from the mnemonic text exactly as typed,
so a double space, a tab or a trailing newline gave a different key,
and a vault made that way did not open with the same words typed
normally. agehd.DeriveEntropy, which init, vault create, vault import,
unlocker add and every unlock go through, now joins the words with
single spaces and puts them in Unicode NFKD, as BIP39 defines the
seed's input, before hashing them. golang.org/x/text, already an
indirect dependency, becomes a direct one for the NFKD step.
Judgement call: internal/bip39's NewSeed keeps hashing its input as
given, as upstream does; the normalising is in agehd.
Model: opus-5-5