cnct+lnwl+hswc: use lntypes.Preimage for witness beacon

lnwallet/interface.go

@@ -9,6 +9,7 @@ import (
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/wire"
 	"github.com/btcsuite/btcutil"
+	"github.com/lightningnetwork/lnd/lntypes"
 )
 
 // AddressType is an enum-like type which denotes the possible address types
@@ -272,15 +273,12 @@ type PreimageCache interface {
 	// LookupPreimage attempts to look up a preimage according to its hash.
 	// If found, the preimage is returned along with true for the second
 	// argument. Otherwise, it'll return false.
-	LookupPreimage(hash []byte) ([]byte, bool)
+	LookupPreimage(hash lntypes.Hash) (lntypes.Preimage, bool)
 
 	// AddPreimages adds a batch of newly discovered preimages to the global
 	// cache, and also signals any subscribers of the newly discovered
 	// witness.
-	//
-	// NOTE: The backing slice of MUST NOT be modified, otherwise the
-	// subscribers may be notified of the incorrect preimages.
-	AddPreimages(preimages ...[]byte) error
+	AddPreimages(preimages ...lntypes.Preimage) error
 }
 
 // WalletDriver represents a "driver" for a particular concrete