update to support bip375

diff --git a/src/main/java/com/sparrowwallet/sparrow/AppController.java b/src/main/java/com/sparrowwallet/sparrow/AppController.java
index 659685c..eccfb4a 100644
--- a/src/main/java/com/sparrowwallet/sparrow/AppController.java
+++ b/src/main/java/com/sparrowwallet/sparrow/AppController.java
@@ -1911,7 +1911,7 @@ public class AppController implements Initializable {
     }
 
     private void addTransactionTab(String name, File file, PSBT psbt) {
-        //Convert to PSBTv0 first
+        //Convert to PSBTv0 first as the consistent internal representation
         if(psbt.getVersion() != null && psbt.getVersion() >= 2) {
             psbt.convertVersion(0);
         }
diff --git a/src/main/java/com/sparrowwallet/sparrow/control/QRScanDialog.java b/src/main/java/com/sparrowwallet/sparrow/control/QRScanDialog.java
index ec6a92c..4f4e290 100644
--- a/src/main/java/com/sparrowwallet/sparrow/control/QRScanDialog.java
+++ b/src/main/java/com/sparrowwallet/sparrow/control/QRScanDialog.java
@@ -656,7 +656,7 @@ public class QRScanDialog extends Dialog<QRScanDialog.Result> {
 
                 List<ChildNumber> path = cryptoKeypath.getComponents().stream().map(comp -> (IndexPathComponent)comp)
                         .map(comp -> new ChildNumber(comp.getIndex(), comp.isHardened())).collect(Collectors.toList());
-                String fingerprint = cryptoKeypath.getSourceFingerprint() == null ? KeystoreController.DEFAULT_WATCH_ONLY_FINGERPRINT : Utils.bytesToHex(cryptoKeypath.getSourceFingerprint());
+                String fingerprint = cryptoKeypath.getSourceFingerprint() == null ? KeyDerivation.DEFAULT_WATCH_ONLY_FINGERPRINT : Utils.bytesToHex(cryptoKeypath.getSourceFingerprint());
                 return new KeyDerivation(fingerprint, KeyDerivation.writePath(path));
             }
 
diff --git a/src/main/java/com/sparrowwallet/sparrow/io/Descriptor.java b/src/main/java/com/sparrowwallet/sparrow/io/Descriptor.java
index e836ab2..d3caae6 100644
--- a/src/main/java/com/sparrowwallet/sparrow/io/Descriptor.java
+++ b/src/main/java/com/sparrowwallet/sparrow/io/Descriptor.java
@@ -140,7 +140,7 @@ public class Descriptor implements WalletImport, WalletExport {
     private static Wallet ensureKeyDerivations(Wallet wallet) {
         for(Keystore keystore : wallet.getKeystores()) {
             if(keystore.getKeyDerivation().getMasterFingerprint() == null || keystore.getKeyDerivation().getDerivationPath() == null) {
-                keystore.setKeyDerivation(new KeyDerivation(KeystoreController.DEFAULT_WATCH_ONLY_FINGERPRINT, wallet.getScriptType().getDefaultDerivationPath()));
+                keystore.setKeyDerivation(new KeyDerivation(KeyDerivation.DEFAULT_WATCH_ONLY_FINGERPRINT, wallet.getScriptType().getDefaultDerivationPath()));
             }
         }
 
diff --git a/src/main/java/com/sparrowwallet/sparrow/keystoreimport/KeystoreImportDialog.java b/src/main/java/com/sparrowwallet/sparrow/keystoreimport/KeystoreImportDialog.java
index c02c415..14c322f 100644
--- a/src/main/java/com/sparrowwallet/sparrow/keystoreimport/KeystoreImportDialog.java
+++ b/src/main/java/com/sparrowwallet/sparrow/keystoreimport/KeystoreImportDialog.java
@@ -82,7 +82,7 @@ public class KeystoreImportDialog extends Dialog<Keystore> {
         keystore.setLabel(existingLabel);
         keystore.setSource(KeystoreSource.SW_WATCH);
         keystore.setWalletModel(WalletModel.SPARROW);
-        keystore.setKeyDerivation(new KeyDerivation(KeystoreController.DEFAULT_WATCH_ONLY_FINGERPRINT, scriptType.getDefaultDerivationPath()));
+        keystore.setKeyDerivation(new KeyDerivation(KeyDerivation.DEFAULT_WATCH_ONLY_FINGERPRINT, scriptType.getDefaultDerivationPath()));
         return keystore;
     }
 
diff --git a/src/main/java/com/sparrowwallet/sparrow/terminal/wallet/WatchOnlyDialog.java b/src/main/java/com/sparrowwallet/sparrow/terminal/wallet/WatchOnlyDialog.java
index 655858e..b698027 100644
--- a/src/main/java/com/sparrowwallet/sparrow/terminal/wallet/WatchOnlyDialog.java
+++ b/src/main/java/com/sparrowwallet/sparrow/terminal/wallet/WatchOnlyDialog.java
@@ -20,8 +20,6 @@ import org.slf4j.LoggerFactory;
 
 import java.util.*;
 
-import static com.sparrowwallet.sparrow.wallet.KeystoreController.DEFAULT_WATCH_ONLY_FINGERPRINT;
-
 public class WatchOnlyDialog extends NewWalletDialog {
     private static final Logger log = LoggerFactory.getLogger(WatchOnlyDialog.class);
 
@@ -126,7 +124,7 @@ public class WatchOnlyDialog extends NewWalletDialog {
             Keystore keystore = new Keystore();
             keystore.setSource(KeystoreSource.SW_WATCH);
             keystore.setWalletModel(WalletModel.SPARROW);
-            keystore.setKeyDerivation(new KeyDerivation(DEFAULT_WATCH_ONLY_FINGERPRINT, scriptType.getDefaultDerivationPath()));
+            keystore.setKeyDerivation(new KeyDerivation(KeyDerivation.DEFAULT_WATCH_ONLY_FINGERPRINT, scriptType.getDefaultDerivationPath()));
             keystore.setExtendedPublicKey(xpub);
             wallet.makeLabelsUnique(keystore);
             wallet.getKeystores().add(keystore);
diff --git a/src/main/java/com/sparrowwallet/sparrow/wallet/KeystoreController.java b/src/main/java/com/sparrowwallet/sparrow/wallet/KeystoreController.java
index fb56d11..4d712c4 100644
--- a/src/main/java/com/sparrowwallet/sparrow/wallet/KeystoreController.java
+++ b/src/main/java/com/sparrowwallet/sparrow/wallet/KeystoreController.java
@@ -44,8 +44,6 @@ import static com.sparrowwallet.sparrow.io.CardApi.isReaderAvailable;
 public class KeystoreController extends WalletFormController implements Initializable {
     private static final Logger log = LoggerFactory.getLogger(KeystoreController.class);
 
-    public static final String DEFAULT_WATCH_ONLY_FINGERPRINT = "00000000";
-
     private Keystore keystore;
 
     @FXML
@@ -252,7 +250,7 @@ public class KeystoreController extends WalletFormController implements Initiali
         if(keystoreSource != KeystoreSource.SW_WATCH) {
             launchImportDialog(keystoreSource);
         } else {
-            fingerprint.setText(DEFAULT_WATCH_ONLY_FINGERPRINT);
+            fingerprint.setText(KeyDerivation.DEFAULT_WATCH_ONLY_FINGERPRINT);
             derivation.setText(getWalletForm().getWallet().getScriptType().getDefaultDerivationPath());
             selectSourcePane.setVisible(false);
         }