channeldb: add MarkConfirmationHeight to OpenChannel

diff --git a/channeldb/channel.go b/channeldb/channel.go
index e16537f..d576475 100644
--- a/channeldb/channel.go
+++ b/channeldb/channel.go
@@ -261,6 +261,10 @@ type openChannelTlvData struct {
 	// customBlob is an optional TLV encoded blob of data representing
 	// custom channel funding information.
 	customBlob tlv.OptionalRecordT[tlv.TlvType7, tlv.Blob]
+
+	// confirmationHeight records the block height at which the funding
+	// transaction was first confirmed.
+	confirmationHeight tlv.RecordT[tlv.TlvType8, uint32]
 }
 
 // encode serializes the openChannelTlvData to the given io.Writer.
@@ -270,6 +274,7 @@ func (c *openChannelTlvData) encode(w io.Writer) error {
 		c.initialLocalBalance.Record(),
 		c.initialRemoteBalance.Record(),
 		c.realScid.Record(),
+		c.confirmationHeight.Record(),
 	}
 	c.memo.WhenSome(func(memo tlv.RecordT[tlv.TlvType5, []byte]) {
 		tlvRecords = append(tlvRecords, memo.Record())
@@ -283,6 +288,8 @@ func (c *openChannelTlvData) encode(w io.Writer) error {
 		tlvRecords = append(tlvRecords, blob.Record())
 	})
 
+	tlv.SortRecords(tlvRecords)
+
 	// Create the tlv stream.
 	tlvStream, err := tlv.NewStream(tlvRecords...)
 	if err != nil {
@@ -307,6 +314,7 @@ func (c *openChannelTlvData) decode(r io.Reader) error {
 		memo.Record(),
 		tapscriptRoot.Record(),
 		blob.Record(),
+		c.confirmationHeight.Record(),
 	)
 	if err != nil {
 		return err
@@ -906,6 +914,10 @@ type OpenChannel struct {
 	// been confirmed before a certain height.
 	FundingBroadcastHeight uint32
 
+	// ConfirmationHeight records the block height at which the funding
+	// transaction was first confirmed.
+	ConfirmationHeight uint32
+
 	// NumConfsRequired is the number of confirmations a channel's funding
 	// transaction must have received in order to be considered available
 	// for normal transactional use.
@@ -1207,6 +1219,7 @@ func (c *OpenChannel) amendTlvData(auxData openChannelTlvData) {
 		auxData.initialRemoteBalance.Val,
 	)
 	c.confirmedScid = auxData.realScid.Val
+	c.ConfirmationHeight = auxData.confirmationHeight.Val
 
 	auxData.memo.WhenSomeV(func(memo []byte) {
 		c.Memo = memo
@@ -1234,6 +1247,9 @@ func (c *OpenChannel) extractTlvData() openChannelTlvData {
 		realScid: tlv.NewRecordT[tlv.TlvType4](
 			c.confirmedScid,
 		),
+		confirmationHeight: tlv.NewPrimitiveRecord[tlv.TlvType8](
+			c.ConfirmationHeight,
+		),
 	}
 
 	if len(c.Memo) != 0 {
@@ -1501,6 +1517,37 @@ func (c *OpenChannel) fullSync(tx kvdb.RwTx) error {
 	return putOpenChannel(chanBucket, c)
 }
 
+// MarkConfirmationHeight updates the channel's confirmation height once the
+// channel opening transaction receives one confirmation.
+func (c *OpenChannel) MarkConfirmationHeight(height uint32) error {
+	c.Lock()
+	defer c.Unlock()
+
+	if err := kvdb.Update(c.Db.backend, func(tx kvdb.RwTx) error {
+		chanBucket, err := fetchChanBucketRw(
+			tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
+		)
+		if err != nil {
+			return err
+		}
+
+		channel, err := fetchOpenChannel(chanBucket, &c.FundingOutpoint)
+		if err != nil {
+			return err
+		}
+
+		channel.ConfirmationHeight = height
+
+		return putOpenChannel(chanBucket, channel)
+	}, func() {}); err != nil {
+		return err
+	}
+
+	c.ConfirmationHeight = height
+
+	return nil
+}
+
 // MarkAsOpen marks a channel as fully open given a locator that uniquely
 // describes its location within the chain.
 func (c *OpenChannel) MarkAsOpen(openLoc lnwire.ShortChannelID) error {
diff --git a/channeldb/channel_test.go b/channeldb/channel_test.go
index cd7d8db..4750406 100644
--- a/channeldb/channel_test.go
+++ b/channeldb/channel_test.go
@@ -978,6 +978,73 @@ func TestChannelStateTransition(t *testing.T) {
 	require.Empty(t, fwdPkgs, "no forwarding packages should exist")
 }
 
+// TestOpeningChannelTxConfirmation verifies that calling MarkConfirmationHeight
+// correctly updates the confirmed state. It also ensures that calling Refresh
+// on a different OpenChannel updates its in-memory state to reflect the prior
+// MarkConfirmationHeight call.
+func TestOpeningChannelTxConfirmation(t *testing.T) {
+	t.Parallel()
+
+	fullDB, err := MakeTestDB(t)
+	require.NoError(t, err)
+
+	cdb := fullDB.ChannelStateDB()
+
+	// Create a pending channel that was broadcast at height 99.
+	const broadcastHeight = uint32(99)
+	channelState := createTestChannel(
+		t, cdb, pendingHeightOption(broadcastHeight),
+	)
+
+	// Fetch pending channels from the database.
+	pendingChannels, err := cdb.FetchPendingChannels()
+	require.NoError(t, err)
+	require.Len(t, pendingChannels, 1)
+
+	// Verify the broadcast height of the pending channel.
+	require.Equal(
+		t, broadcastHeight, pendingChannels[0].FundingBroadcastHeight,
+	)
+
+	confirmationHeight := broadcastHeight + 1
+
+	// Mark the channel's confirmation height.
+	err = pendingChannels[0].MarkConfirmationHeight(confirmationHeight)
+	require.NoError(t, err)
+
+	// Verify the ConfirmationHeight is updated correctly.
+	require.Equal(
+		t, confirmationHeight, pendingChannels[0].ConfirmationHeight,
+	)
+
+	// Re-fetch the pending channels to confirm persistence.
+	pendingChannels, err = cdb.FetchPendingChannels()
+	require.NoError(t, err)
+	require.Len(t, pendingChannels, 1)
+
+	// Validate the confirmation and broadcast height.
+	require.Equal(
+		t, confirmationHeight, pendingChannels[0].ConfirmationHeight,
+	)
+	require.Equal(
+		t, broadcastHeight, pendingChannels[0].FundingBroadcastHeight,
+	)
+
+	// Ensure the original channel state's confirmation height is not
+	// updated before refresh.
+	require.EqualValues(t, channelState.ConfirmationHeight, 0)
+
+	// Refresh the original channel state.
+	err = channelState.Refresh()
+	require.NoError(t, err)
+
+	// Verify that both channel states now have the same ConfirmationHeight.
+	require.Equal(
+		t, channelState.ConfirmationHeight,
+		pendingChannels[0].ConfirmationHeight,
+	)
+}
+
 func TestFetchPendingChannels(t *testing.T) {
 	t.Parallel()
 
@@ -1007,7 +1074,7 @@ func TestFetchPendingChannels(t *testing.T) {
 	}
 
 	chanOpenLoc := lnwire.ShortChannelID{
-		BlockHeight: 5,
+		BlockHeight: broadcastHeight + 1,
 		TxIndex:     10,
 		TxPosition:  15,
 	}