multi: start consumers with a starting blockbeat

This is needed so the consumers have an initial state about the current
block.

contractcourt/chain_arbitrator.go

@@ -570,13 +570,16 @@ func (c *ChainArbitrator) ResolveContract(chanPoint wire.OutPoint) error {
 }
 
 // Start launches all goroutines that the ChainArbitrator needs to operate.
-func (c *ChainArbitrator) Start() error {
+func (c *ChainArbitrator) Start(beat chainio.Blockbeat) error {
 	if !atomic.CompareAndSwapInt32(&c.started, 0, 1) {
 		return nil
 	}
 
-	log.Infof("ChainArbitrator starting with config: budget=[%v]",
-		&c.cfg.Budget)
+	// Set the current beat.
+	c.beat = beat
+
+	log.Infof("ChainArbitrator starting at height %d with budget=[%v]",
+		&c.cfg.Budget, c.beat.Height())
 
 	// First, we'll fetch all the channels that are still open, in order to
 	// collect them within our set of active contracts.

contractcourt/chain_arbitrator_test.go

@@ -90,7 +90,8 @@ func TestChainArbitratorRepublishCloses(t *testing.T) {
 		chainArbCfg, db,
 	)
 
-	if err := chainArb.Start(); err != nil {
+	beat := newBeatFromHeight(0)
+	if err := chainArb.Start(beat); err != nil {
 		t.Fatal(err)
 	}
 	t.Cleanup(func() {
@@ -173,7 +174,8 @@ func TestResolveContract(t *testing.T) {
 	chainArb := NewChainArbitrator(
 		chainArbCfg, db,
 	)
-	if err := chainArb.Start(); err != nil {
+	beat := newBeatFromHeight(0)
+	if err := chainArb.Start(beat); err != nil {
 		t.Fatal(err)
 	}
 	t.Cleanup(func() {