fix(wallet): GUI bootstrap calls DownloadUtxoSnapshot, not legacy

The QT wallet's IntroDialog was calling Bootstrap::DownloadBootstrap(),
which always returns false ('Legacy file-list bootstrap is disabled').
Fresh wallet installs would show 'Could not download blockchain snapshot'
and fall back to slow genesis sync.

Fix: call DownloadUtxoSnapshot first (matches daemon init.cpp behavior),
fall back to legacy path for diagnostics. Also adds checkpoint + snapshot
hash for height 2,219,922 so the v6.2.5.0 snapshot can be verified by
fresh installs.

src/checkpoints.cpp

@@ -52,6 +52,10 @@ namespace Checkpoints
                 { 2213000, uint256("0x7bc9652d423676c52ba8b0a287e0b46e1eca6e8eecc51d3f30e0d665d3b236f5")},
                 { 2214000, uint256("0x17e61ceb45db36358aaabe91b094a77ecba32370a467185fa9af75eef6c8e414")},
                 { 2214400, uint256("0x8ebb818f7280850c5a3916b7c8a2bca603f7c4f9926d3cdc2262f726035d96ed")},
+                // Post-rebuild finality pin (v6.2.5.0). Closes the gap between
+                // the last hardcoded checkpoint and the live tip after -rebuildutxo.
+                // Hash from the canonical chain on DNS2 after fresh UTXO rebuild.
+                { 2219922, uint256("0x9ed3e1d38317950927f37f2867e3fc29e239fc1f4c57b182f55c6e04b73b52ec")},
             };
 
     // Published UTXO snapshot file SHA256, keyed by snapshot height.
@@ -64,6 +68,7 @@ namespace Checkpoints
     // mapCheckpoints / mapCheckpointsTestnet.
     static std::map<int, uint256> mapSnapshotHashes = {
         { 2206004, uint256("0x1419282dae817315ee1b955543f6248233fe5800f5e8488734a0ece5bd6781ea")},
+        { 2219922, uint256("0x6dd8d782a04bb8dc4ccd5e88a4bc7726fe26bdebaed96b79242de1e2949b6ee6")},
     };
 
     static std::map<int, uint256> mapSnapshotHashesTestnet = {
@@ -353,14 +358,14 @@ namespace Checkpoints
 
     bool SetCheckpointPrivKey(std::string strPrivKey)
     {
-        (void)strPrivKey;
+        (void)strPrivKey;
-        return error("SetCheckpointPrivKey: synchronized checkpoints are disabled");
+        return error("SetCheckpointPrivKey: synchronized checkpoints are disabled");
     }
 
     bool SendSyncCheckpoint(uint256 hashCheckpoint)
     {
-        (void)hashCheckpoint;
+        (void)hashCheckpoint;
-        return error("SendSyncCheckpoint: synchronized checkpoints are disabled");
+        return error("SendSyncCheckpoint: synchronized checkpoints are disabled");
     }
 
     // Is the sync-checkpoint outside maturity window?
@@ -381,11 +386,11 @@ const std::string CSyncCheckpoint::strMasterPubKey = "";
 std::string CSyncCheckpoint::strMasterPrivKey = "";
 
 // triangles: verify signature of sync-checkpoint message
-// The master-key system is disabled. Reject these legacy messages instead of
+// The master-key system is disabled. Reject these legacy messages instead of
-// treating unsigned data as authenticated if a dispatcher is added later.
+// treating unsigned data as authenticated if a dispatcher is added later.
 bool CSyncCheckpoint::CheckSignature()
 {
-    return error("CSyncCheckpoint::CheckSignature: synchronized checkpoints are disabled");
+    return error("CSyncCheckpoint::CheckSignature: synchronized checkpoints are disabled");
 }
 
 // triangles: process synchronized checkpoint

src/qt/introdialog.cpp

@@ -291,7 +291,22 @@ bool IntroDialog::pickDataDirectory()
                 QApplication::processEvents();
             };
 
-            bool success = Bootstrap::DownloadBootstrap(host, dataDirPath, progressFn, strError);
+            // Try the fast UTXO snapshot path first (matches daemon behavior in init.cpp).
+            // The legacy DownloadBootstrap() is hard-disabled in bootstrap.cpp — it always
+            // returns false with "Legacy file-list bootstrap is disabled". Calling it here
+            // would make the GUI wallet unable to bootstrap a fresh install.
+            std::string utxoError;
+            bool success = Bootstrap::DownloadUtxoSnapshot(host, dataDirPath, progressFn, utxoError);
+            if (!success) {
+                // Fall back to legacy bootstrap path (will fail with "disabled" error, but
+                // surfaces the real error if the snapshot path had a different failure).
+                std::string legacyError;
+                if (Bootstrap::DownloadBootstrap(host, dataDirPath, progressFn, legacyError)) {
+                    success = true;
+                } else {
+                    strError = "UTXO snapshot: " + utxoError + " | Legacy: " + legacyError;
+                }
+            }
             if (!success) {
                 QMessageBox::warning(0, "Triangles",
                     QString("Could not download blockchain snapshot:\n%1\n\n"