feat: show Bitcoin master fingerprint in wallet keys (#3489)

* feat: show Bitcoin master fingerprint in wallet keys

Add the BIP-32 master fingerprint (XFP) to the Bitcoin wallet keys shown
under Settings > Seed & Keys > Keys, labeled "Master fingerprint".

* fix: keep xPub in Keys tab by splitting silent payment keys into a dedicated list

The Keys tab / Silent Payments tab split relied on a hardcoded item index
(`items.sublist(0, 4)` / `sublist(4)`) that assumed the first four items
were always WIF/private key/public key/xPub. Adding the master fingerprint
as the first item pushed xPub into the Silent Payments tab.

Route Bitcoin silent payment keys into their own `silentPaymentItems` list
instead, and render each tab from its list.

cw_bitcoin/lib/bitcoin_wallet_keys.dart

@@ -1,12 +1,23 @@
 class BitcoinWalletKeys {
-  const BitcoinWalletKeys(
-      {required this.wif, required this.privateKey, required this.publicKey, required this.xpub});
+  const BitcoinWalletKeys({
+    required this.wif,
+    required this.privateKey,
+    required this.publicKey,
+    required this.xpub,
+    this.masterFingerprint = '',
+  });
 
   final String wif;
   final String privateKey;
   final String publicKey;
   final String xpub;
+  final String masterFingerprint;
 
-  Map<String, String> toJson() =>
-      {'wif': wif, 'privateKey': privateKey, 'publicKey': publicKey, 'xpub': xpub};
+  Map<String, String> toJson() => {
+        'wif': wif,
+        'privateKey': privateKey,
+        'publicKey': publicKey,
+        'xpub': xpub,
+        'masterFingerprint': masterFingerprint,
+      };
 }

cw_bitcoin/lib/electrum_wallet.dart

@@ -471,6 +471,7 @@ abstract class ElectrumWalletBase
       privateKey: privateKey ?? '',
       publicKey: publicKey ?? '',
       xpub: xpub,
+      masterFingerprint: _masterHD?.fingerPrint.toHex() ?? '',
     );
   }
 

lib/src/screens/wallet_keys/wallet_keys_page.dart

@@ -78,7 +78,7 @@ class _WalletKeysPageBodyState extends State<WalletKeysPageBody>
 
     showKeyTab = widget.walletKeysViewModel.items.isNotEmpty;
     showSilentPaymentsTab =
-        widget.walletKeysViewModel.isBitcoin && widget.walletKeysViewModel.items.length > 4;
+        widget.walletKeysViewModel.isBitcoin && widget.walletKeysViewModel.silentPaymentItems.isNotEmpty;
     showLegacySeedTab = widget.walletKeysViewModel.legacySeedSplit.isNotEmpty;
     isLegacySeedOnly = widget.walletKeysViewModel.isLegacySeedOnly;
 
@@ -157,16 +157,12 @@ class _WalletKeysPageBodyState extends State<WalletKeysPageBody>
                 if (showKeyTab)
                   Padding(
                     padding: const EdgeInsets.only(left: 22, right: 22),
-                    child: _buildKeysTab(
-                        context,
-                        showSilentPaymentsTab
-                            ? widget.walletKeysViewModel.items.sublist(0, 4)
-                            : widget.walletKeysViewModel.items),
+                    child: _buildKeysTab(context, widget.walletKeysViewModel.items),
                   ),
                 if (showSilentPaymentsTab)
                   Padding(
                     padding: const EdgeInsets.only(left: 22, right: 22),
-                    child: _buildKeysTab(context, widget.walletKeysViewModel.items.sublist(4)),
+                    child: _buildKeysTab(context, widget.walletKeysViewModel.silentPaymentItems),
                   ),
                 if (showLegacySeedTab)
                   Padding(

lib/view_model/wallet_keys_view_model.dart

@@ -30,6 +30,7 @@ abstract class WalletKeysViewModelBase with Store {
         _restoreHeight = _appStore.wallet!.walletInfo.restoreHeight,
         _restoreHeightByTransactions = 0,
         items = ObservableList<StandartListItem>(),
+        silentPaymentItems = ObservableList<StandartListItem>(),
         _title = _getInitialTitle(_appStore.wallet!) {
     _populateKeysItems();
 
@@ -87,6 +88,7 @@ abstract class WalletKeysViewModelBase with Store {
   // this is incomplete, needs legacy seed toggle for XMR
   bool get shouldShowHeightBox => [WalletType.bitcoin, WalletType.zcash].contains(_wallet.type);
   final ObservableList<StandartListItem> items;
+  final ObservableList<StandartListItem> silentPaymentItems;
 
   @observable
   String _title;
@@ -150,6 +152,7 @@ abstract class WalletKeysViewModelBase with Store {
 
   void _populateKeysItems() {
     items.clear();
+    silentPaymentItems.clear();
 
     Map<String, String>? keys;
 
@@ -217,6 +220,11 @@ abstract class WalletKeysViewModelBase with Store {
         final electrumKeys = bitcoin!.getWalletKeys(_appStore.wallet!);
 
         items.addAll([
+          if ((electrumKeys['masterFingerprint'] ?? '').isNotEmpty)
+            StandartListItem(
+              title: "Master fingerprint",
+              value: electrumKeys['masterFingerprint']!,
+            ),
           if ((electrumKeys['wif'] ?? '').isNotEmpty)
             StandartListItem(title: "WIF", value: electrumKeys['wif']!),
           if ((electrumKeys['privateKey'] ?? '').isNotEmpty)
@@ -233,7 +241,8 @@ abstract class WalletKeysViewModelBase with Store {
     }
 
     if (keys != null) {
-      items.addAll([
+      final keysList = _wallet.type == WalletType.bitcoin ? silentPaymentItems : items;
+      keysList.addAll([
         if ((keys['primaryAddress'] ?? '').isNotEmpty)
           StandartListItem(
               key: ValueKey('${_walletName}_wallet_primary_address_item_key'),