chore: move the go code into a subfolder

apps/api/internal/repository/milestone/aggregate.go

@@ -0,0 +1,33 @@
+package milestone
+
+import (
+	"context"
+
+	"github.com/zitadel/zitadel/internal/api/authz"
+	"github.com/zitadel/zitadel/internal/eventstore"
+)
+
+const (
+	AggregateType    = "milestone"
+	AggregateVersion = "v2"
+)
+
+type Aggregate struct {
+	eventstore.Aggregate
+}
+
+func NewAggregate(ctx context.Context) *Aggregate {
+	return NewInstanceAggregate(authz.GetInstance(ctx).InstanceID())
+}
+
+func NewInstanceAggregate(instanceID string) *Aggregate {
+	return &Aggregate{
+		Aggregate: eventstore.Aggregate{
+			Type:          AggregateType,
+			Version:       AggregateVersion,
+			ID:            instanceID,
+			ResourceOwner: instanceID,
+			InstanceID:    instanceID,
+		},
+	}
+}