input+lnwallet: update taproot scripts to accept optional aux leaf

In this commit, we update all the taproot scripts to also accept an
optional aux leaf. This aux leaf can be used to add more redemption
paths for advanced channels, or just as an extra commitment space.

watchtower/blob/justice_kit.go

@@ -10,6 +10,7 @@ import (
 	"github.com/btcsuite/btcd/txscript"
 	"github.com/btcsuite/btcd/wire"
 	secp "github.com/decred/dcrd/dcrec/secp256k1/v4"
+	"github.com/lightningnetwork/lnd/fn"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/lnwallet"
 	"github.com/lightningnetwork/lnd/lnwire"
@@ -307,9 +308,11 @@ func newTaprootJusticeKit(sweepScript []byte,
 
 	keyRing := breachInfo.KeyRing
 
+	// TODO(roasbeef): aux leaf tower updates needed
+
 	tree, err := input.NewLocalCommitScriptTree(
 		breachInfo.RemoteDelay, keyRing.ToLocalKey,
-		keyRing.RevocationKey,
+		keyRing.RevocationKey, fn.None[txscript.TapLeaf](),
 	)
 	if err != nil {
 		return nil, err
@@ -416,7 +419,9 @@ func (t *taprootJusticeKit) ToRemoteOutputSpendInfo() (*txscript.PkScript,
 		return nil, nil, 0, err
 	}
 
-	scriptTree, err := input.NewRemoteCommitScriptTree(toRemotePk)
+	scriptTree, err := input.NewRemoteCommitScriptTree(
+		toRemotePk, fn.None[txscript.TapLeaf](),
+	)
 	if err != nil {
 		return nil, nil, 0, err
 	}

watchtower/blob/justice_kit_test.go

@@ -12,6 +12,7 @@ import (
 	"github.com/btcsuite/btcd/btcec/v2/schnorr"
 	"github.com/btcsuite/btcd/txscript"
 	"github.com/btcsuite/btcd/wire"
+	"github.com/lightningnetwork/lnd/fn"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/lnwallet"
 	"github.com/lightningnetwork/lnd/lnwire"
@@ -304,7 +305,9 @@ func TestJusticeKitRemoteWitnessConstruction(t *testing.T) {
 			name:     "taproot commitment",
 			blobType: TypeAltruistTaprootCommit,
 			expWitnessScript: func(pk *btcec.PublicKey) []byte {
-				tree, _ := input.NewRemoteCommitScriptTree(pk)
+				tree, _ := input.NewRemoteCommitScriptTree(
+					pk, fn.None[txscript.TapLeaf](),
+				)
 
 				return tree.SettleLeaf.Script
 			},
@@ -461,6 +464,7 @@ func TestJusticeKitToLocalWitnessConstruction(t *testing.T) {
 
 				script, _ := input.NewLocalCommitScriptTree(
 					csvDelay, delay, rev,
+					fn.None[txscript.TapLeaf](),
 				)
 
 				return script.RevocationLeaf.Script