paymentsdb: normalize orphaned blinded total

diff --git a/payments/db/migration1/migration_validation.go b/payments/db/migration1/migration_validation.go
index c81303e..7b239d2 100644
--- a/payments/db/migration1/migration_validation.go
+++ b/payments/db/migration1/migration_validation.go
@@ -394,11 +394,26 @@ func normalizePaymentForCompare(payment *MPPayment) {
 		}
 
 		for j := range htlc.Route.Hops {
-			if len(htlc.Route.Hops[j].CustomRecords) == 0 {
-				htlc.Route.Hops[j].CustomRecords =
+			hop := htlc.Route.Hops[j]
+			if len(hop.CustomRecords) == 0 {
+				hop.CustomRecords =
 					record.CustomSet{}
 			}
 
+			// The migration treats nil and empty encrypted data as
+			// absent, so it omits the blinded child row. SQL reads
+			// the hop back with nil encrypted data and a zero
+			// total. Apply the same transformation to the KV
+			// copy before comparing the payments. A blinding point
+			// without data is rejected during migration, so it
+			// cannot reach this comparison.
+			if len(hop.EncryptedData) == 0 &&
+				hop.BlindingPoint == nil {
+
+				hop.EncryptedData = nil
+				hop.TotalAmtMsat = 0
+			}
+
 			// LegacyPayload was a hint used by the KV store to
 			// determine how to serialize and deserialize the hop
 			// payload (i.e. whether to use the legacy format or
@@ -406,7 +421,7 @@ func normalizePaymentForCompare(payment *MPPayment) {
 			// all — each field is stored natively in its own
 			// column — so this flag has no meaning there and is
 			// never persisted.
-			htlc.Route.Hops[j].LegacyPayload = false
+			hop.LegacyPayload = false
 		}
 	}
 }
diff --git a/payments/db/migration1/sql_migration.go b/payments/db/migration1/sql_migration.go
index a353766..9e187b8 100644
--- a/payments/db/migration1/sql_migration.go
+++ b/payments/db/migration1/sql_migration.go
@@ -734,8 +734,12 @@ func migrateHTLCAttempt(ctx context.Context, paymentID int64,
 	// Insert route hops.
 	for hopIndex := range htlc.Route.Hops {
 		hop := htlc.Route.Hops[hopIndex]
+
+		// Use the parent hash for diagnostics. For AMP payments this
+		// is the set ID, which identifies the payment containing the
+		// shard.
 		err = migrateRouteHop(
-			ctx, attemptIndex, hopIndex, hop,
+			ctx, parentPaymentHash, attemptIndex, hopIndex, hop,
 			sqlDB, stats,
 		)
 		if err != nil {
@@ -807,8 +811,8 @@ func migrateHTLCAttempt(ctx context.Context, paymentID int64,
 
 // migrateRouteHop migrates a single route hop.
 func migrateRouteHop(ctx context.Context,
-	attemptID int64, hopIndex int, hop *Hop, sqlDB SQLQueries,
-	stats *MigrationStats) error {
+	parentPaymentHash lntypes.Hash, attemptIndex int64, hopIndex int,
+	hop *Hop, sqlDB SQLQueries, stats *MigrationStats) error {
 
 	// Convert channel ID to string representation of uint64.
 	// The SCID is stored as a decimal string to match the converter
@@ -817,7 +821,7 @@ func migrateRouteHop(ctx context.Context,
 
 	// Insert route hop.
 	hopID, err := sqlDB.InsertRouteHop(ctx, sqlc.InsertRouteHopParams{
-		HtlcAttemptIndex: attemptID,
+		HtlcAttemptIndex: attemptIndex,
 		HopIndex:         int32(hopIndex),
 		PubKey:           hop.PubKeyBytes[:],
 		Scid:             scidStr,
@@ -829,10 +833,35 @@ func migrateRouteHop(ctx context.Context,
 		return fmt.Errorf("insert hop: %w", err)
 	}
 
-	// Check for blinded route data (route blinding).
-	if len(hop.EncryptedData) > 0 || hop.BlindingPoint != nil ||
-		hop.TotalAmtMsat != 0 {
+	// Non-empty encrypted recipient data identifies a blinded hop.
+	// The RPC boundary has required encrypted data with a blinding point
+	// since these fields were introduced. Internally built blinded routes
+	// also always contain both. Unlike an orphaned total, a point without
+	// encrypted data is not a supported legacy encoding. Report it as
+	// malformed instead of silently discarding it. Keep this rejection in
+	// sync with normalizePaymentForCompare, which only normalizes hops
+	// without a blinding point.
+	hasEncryptedData := len(hop.EncryptedData) > 0
+	if !hasEncryptedData && hop.BlindingPoint != nil {
+		return fmt.Errorf("invalid blinded hop: payment_hash=%x, "+
+			"attempt_index=%d, hop=%d: blinding point requires "+
+			"encrypted recipient data", parentPaymentHash[:8],
+			attemptIndex, hopIndex)
+	}
+
+	// SendToRouteV2 historically allowed a blinded total amount without
+	// blinded hop data. Omit such an orphaned total rather than creating a
+	// blinded-hop row.
+	if !hasEncryptedData && hop.TotalAmtMsat != 0 {
+		log.Warnf("Ignoring orphaned blinded total amount: "+
+			"payment_hash=%x, attempt_index=%d, hop=%d, "+
+			"total_amt_msat=%d", parentPaymentHash[:8],
+			attemptIndex, hopIndex, hop.TotalAmtMsat)
+	}
 
+	// The blinding point and total amount are only associated fields. Use
+	// the length so nil and empty encrypted data are handled consistently.
+	if hasEncryptedData {
 		var blindingPoint []byte
 		if hop.BlindingPoint != nil {
 			blindingPoint = hop.BlindingPoint.SerializeCompressed()
diff --git a/payments/db/migration1/sql_migration_test.go b/payments/db/migration1/sql_migration_test.go
index 05b4d12..295f230 100644
--- a/payments/db/migration1/sql_migration_test.go
+++ b/payments/db/migration1/sql_migration_test.go
@@ -940,6 +940,147 @@ func TestMigratePaymentWithBlindedRoute(t *testing.T) {
 	assertPaymentDataMatches(t, ctx, kvDB, sqlStore, paymentHash)
 }
 
+// TestMigrateOrphanedBlindedTotalAmount tests that a blinded total amount
+// without encrypted recipient data is normalized during migration.
+func TestMigrateOrphanedBlindedTotalAmount(t *testing.T) {
+	t.Parallel()
+
+	runTest := func(t *testing.T, hashString string,
+		encryptedData []byte) {
+
+		t.Helper()
+
+		ctx := context.Background()
+		kvDB := setupTestKVDB(t)
+
+		var paymentHash [32]byte
+		copy(paymentHash[:], []byte(hashString))
+
+		err := kvdb.Update(kvDB, func(tx kvdb.RwTx) error {
+			paymentsBucket, err := tx.CreateTopLevelBucket(
+				paymentsRootBucket,
+			)
+			if err != nil {
+				return err
+			}
+
+			indexBucket, err := tx.CreateTopLevelBucket(
+				paymentsIndexBucket,
+			)
+			if err != nil {
+				return err
+			}
+
+			return createTestPayment(
+				t, paymentsBucket, indexBucket,
+				paymentTestConfig{
+					hash:           paymentHash,
+					seqNum:         1,
+					value:          120000,
+					creationTime:   time.Unix(1, 0),
+					paymentRequest: hashString,
+					attemptID:      1,
+					numHops:        1,
+					baseChannelID:  400000,
+					baseTimeLock:   800000,
+					hopConfigurator: func(hop *Hop, _ int,
+						_ bool) {
+
+						hop.EncryptedData = encryptedData
+						hop.TotalAmtMsat = 119400
+					},
+				},
+			)
+		}, func() {})
+		require.NoError(t, err)
+
+		sqlStore := setupTestSQLDB(t)
+		err = runPaymentsMigration(ctx, kvDB, sqlStore)
+		require.NoError(t, err)
+
+		var hash lntypes.Hash
+		copy(hash[:], paymentHash[:])
+		payment, err := sqlStore.FetchPayment(ctx, hash)
+		require.NoError(t, err)
+		require.Zero(
+			t, payment.HTLCs[0].Route.Hops[0].TotalAmtMsat,
+		)
+
+		assertPaymentDataMatches(t, ctx, kvDB, sqlStore, paymentHash)
+	}
+
+	t.Run("nil encrypted data", func(t *testing.T) {
+		runTest(t, "orphaned_total_nil", nil)
+	})
+	t.Run("empty encrypted data", func(t *testing.T) {
+		runTest(t, "orphaned_total_empty", []byte{})
+	})
+}
+
+// TestMigrateBlindingPointWithoutEncryptedData tests that migration reports a
+// malformed blinded hop with enough context to locate the affected attempt.
+func TestMigrateBlindingPointWithoutEncryptedData(t *testing.T) {
+	t.Parallel()
+
+	ctx := context.Background()
+	kvDB := setupTestKVDB(t)
+
+	var paymentHash [32]byte
+	copy(paymentHash[:], []byte("blinding_point_without_data"))
+	var attemptHash lntypes.Hash
+	copy(attemptHash[:], []byte("individual_amp_htlc_hash"))
+
+	err := kvdb.Update(kvDB, func(tx kvdb.RwTx) error {
+		paymentsBucket, err := tx.CreateTopLevelBucket(
+			paymentsRootBucket,
+		)
+		if err != nil {
+			return err
+		}
+
+		indexBucket, err := tx.CreateTopLevelBucket(
+			paymentsIndexBucket,
+		)
+		if err != nil {
+			return err
+		}
+
+		return createTestPayment(
+			t, paymentsBucket, indexBucket, paymentTestConfig{
+				hash:           paymentHash,
+				attemptHash:    &attemptHash,
+				seqNum:         1,
+				value:          120000,
+				creationTime:   time.Unix(1, 0),
+				paymentRequest: "blinding-point-without-data",
+				attemptID:      1,
+				numHops:        1,
+				baseChannelID:  400000,
+				baseTimeLock:   800000,
+				hopConfigurator: func(hop *Hop, _ int, _ bool) {
+					blindingKey, err := btcec.NewPrivateKey()
+					require.NoError(t, err)
+
+					hop.BlindingPoint = blindingKey.PubKey()
+				},
+			},
+		)
+	}, func() {})
+	require.NoError(t, err)
+
+	sqlStore := setupTestSQLDB(t)
+	err = runPaymentsMigration(ctx, kvDB, sqlStore)
+	require.ErrorContains(t, err, "blinding point requires encrypted "+
+		"recipient data")
+	require.ErrorContains(t, err, "attempt_index=1, hop=0")
+	require.ErrorContains(t, err, fmt.Sprintf(
+		"payment_hash=%x", paymentHash[:8],
+	))
+	require.NotContains(t, err.Error(), fmt.Sprintf(
+		"payment_hash=%x", attemptHash[:8],
+	))
+}
+
 // TestMigratePaymentWithMetadata tests migration of a payment with hop
 // metadata.
 func TestMigratePaymentWithMetadata(t *testing.T) {
@@ -1934,6 +2075,7 @@ func assertPaymentDataMatches(t *testing.T, ctx context.Context,
 // features.
 type paymentTestConfig struct {
 	hash              [32]byte
+	attemptHash       *lntypes.Hash
 	seqNum            uint64
 	value             lnwire.MilliSatoshi
 	creationTime      time.Time
@@ -2128,6 +2270,11 @@ func createTestPayment(t *testing.T, paymentsBucket, indexBucket kvdb.RwBucket,
 	}
 
 	// Create and serialize attempt info.
+	attemptHash := (*lntypes.Hash)(&cfg.hash)
+	if cfg.attemptHash != nil {
+		attemptHash = cfg.attemptHash
+	}
+
 	attemptInfo := &HTLCAttemptInfo{
 		AttemptID:  cfg.attemptID,
 		sessionKey: sessionKeyBytes,
@@ -2139,7 +2286,7 @@ func createTestPayment(t *testing.T, paymentsBucket, indexBucket kvdb.RwBucket,
 			FirstHopWireCustomRecords: cfg.attemptCustomRecs,
 		},
 		AttemptTime: cfg.creationTime.Add(time.Minute),
-		Hash:        (*lntypes.Hash)(&cfg.hash),
+		Hash:        attemptHash,
 	}
 
 	if err = writeHTLCAttempt(