itest: add sats keysends to cover missing noop_htlc anchors

Many of our itest cases would rely on making multiple asset keysends to
initialize the state for our test case. This would include the
expectation that the receiver would receive enough sats to be able to
pay back the sender. With noop HTLCs the sender only sends the sats to
the receiver iff they are currently below reserve. We add some direct
sats keysends to give the receiver some sats balance to be able to
support sending back asset HTLCs.

Author: GeorgeTsagk

itest/litd_custom_channels_test.go

@@ -1279,16 +1279,23 @@ func testCustomChannelsGroupTranchesForceClose(ctx context.Context,
 	// that transports assets from two tranches.
 	// ------------
 	const (
-		keySendAmount  = 5000
-		numSends       = 6
-		totalFirstSend = keySendAmount * numSends
+		keySendAmount    = 5000
+		keySendSatAmount = 5000
+		numSends         = 6
+		totalFirstSend   = keySendAmount * numSends
 	)
 	for i := 0; i < numSends; i++ {
 		sendAssetKeySendPayment(
 			t.t, charlie, dave, keySendAmount, nil,
 			fn.None[int64](), withGroupKey(groupKey),
 		)
 	}
+
+	// With noop HTLCs implemented the sats balance of Dave will only
+	// increase up to the reserve amount. Let's make a direct non-asset
+	// keysend to make sure the sats balance is also enough.
+	sendKeySendPayment(t.t, charlie, dave, keySendSatAmount)
+
 	logBalanceGroup(t.t, nodes, groupIDs, "after keysend Charlie->Dave")
 
 	// ------------
@@ -1528,8 +1535,9 @@ func testCustomChannelsGroupTranchesHtlcForceClose(ctx context.Context,
 	// First, we'll send over some funds from Charlie to Dave, as we want
 	// Dave to be able to extend HTLCs in the other direction.
 	const (
-		numPayments   = 10
-		keySendAmount = 2_500
+		numPayments      = 10
+		keySendAmount    = 2_500
+		keySendSatAmount = 5000
 	)
 	for i := 0; i < numPayments; i++ {
 		sendAssetKeySendPayment(
@@ -1538,6 +1546,11 @@ func testCustomChannelsGroupTranchesHtlcForceClose(ctx context.Context,
 		)
 	}
 
+	// With noop HTLCs implemented the sats balance of Dave will only
+	// increase up to the reserve amount. Let's make a direct non-asset
+	// keysend to make sure the sats balance is also enough.
+	sendKeySendPayment(t.t, charlie, dave, keySendSatAmount)
+
 	// Now that both parties have some funds, we'll move onto the main test.
 	//
 	// We'll make 2 hodl invoice for each peer, so 4 total. From Charlie's
@@ -4040,16 +4053,25 @@ func runCustomChannelsHtlcForceClose(ctx context.Context, t *harnessTest,
 	// First, we'll send over some funds from Alice to Bob, as we want Bob
 	// to be able to extend HTLCs in the other direction.
 	const (
-		numPayments   = 10
-		keySendAmount = 2_500
+		numPayments        = 10
+		keySendAssetAmount = 2_500
+		keySendSatAmount   = 5_000
 	)
 	for i := 0; i < numPayments; i++ {
 		sendAssetKeySendPayment(
-			t.t, alice, bob, keySendAmount, assetID,
+			t.t, alice, bob, keySendAssetAmount, assetID,
 			fn.None[int64](),
 		)
+
 	}
 
+	// With noop HTLCs implemented the sats balance of Bob will only
+	// increase up to the reserve amount. Let's make a direct non-asset
+	// keysend to make sure the sats balance is also enough.
+	sendKeySendPayment(t.t, alice, bob, keySendSatAmount)
+
+	logBalance(t.t, nodes, assetID, "after keysends to Bob")
+
 	// Now that both parties have some funds, we'll move onto the main test.
 	//
 	// We'll make 2 hodl invoice for each peer, so 4 total. From Alice's