supplycommit: add MintCommitter and BurnSupplyCommitter interfaces

This commit extends the MultiStateMachineManager to implement the
MintCommitter and BurnSupplyCommitter interfaces. These new methods
provide a type-safe way to send mint and burn events to the supply
commitment state machines.

The SendMintEvent method accepts universe-specific types for minting
operations, while SendBurnEvent handles burn leaf submissions. Both
methods internally construct the appropriate event types and delegate
to the existing SendEvent infrastructure, maintaining consistency with
the state machine architecture.

Author: Roasbeef

universe/supplycommit/multi_sm_manager.go

@@ -12,6 +12,7 @@ import (
 	"github.com/lightninglabs/taproot-assets/fn"
 	"github.com/lightninglabs/taproot-assets/mssmt"
 	"github.com/lightninglabs/taproot-assets/tapgarden"
+	"github.com/lightninglabs/taproot-assets/universe"
 	"github.com/lightningnetwork/lnd/msgmux"
 	"github.com/lightningnetwork/lnd/protofsm"
 )
@@ -225,6 +226,30 @@ func (m *MultiStateMachineManager) SendEvent(ctx context.Context,
 	return nil
 }
 
+// SendMintEvent sends a mint event to the supply commitment state machine.
+func (m *MultiStateMachineManager) SendMintEvent(ctx context.Context,
+	assetSpec asset.Specifier, leafKey universe.UniqueLeafKey,
+	issuanceProof universe.Leaf) error {
+
+	mintEvent := &NewMintEvent{
+		LeafKey:       leafKey,
+		IssuanceProof: issuanceProof,
+	}
+
+	return m.SendEvent(ctx, assetSpec, mintEvent)
+}
+
+// SendBurnEvent sends a burn event to the supply commitment state machine.
+func (m *MultiStateMachineManager) SendBurnEvent(ctx context.Context,
+	assetSpec asset.Specifier, burnLeaf universe.BurnLeaf) error {
+
+	burnEvent := &NewBurnEvent{
+		BurnLeaf: burnLeaf,
+	}
+
+	return m.SendEvent(ctx, assetSpec, burnEvent)
+}
+
 // CanHandle determines if the state machine associated with the given asset
 // specifier can handle the given message. If a state machine for the asset
 // group does not exist, it will be created and started.