WalletKeys.entry() built a bech32 p2wpkh address whatever the account
path's purpose, so picking Legacy (D...), Wrapped SegWit (S...) or
Taproot (dgb1p...) in Settings showed a dgb1q address from the BIP44/
49/86 key tree, one no other wallet restoring that path would find.
Each family now derives its own address and script, and spending
supplies what its inputs need (previous tx for P2PKH, redeem script for
P2SH-P2WPKH, tap-tweaked key for Taproot, which is active on DigiByte),
with per-family fee sizes. Unknown purposes are refused instead of
falling back to BIP84.
Also: inputs were signed in selection order but the PSBT orders them by
BIP69, so a spend from two addresses tried to sign each input with the
other's key. They are now signed in the PSBT's order.