fix: add compile time interface checks

hive/handlers/ec2/image/service_impl.go

@@ -17,6 +17,9 @@ import (
 	"github.com/mulgadc/viperblock/viperblock"
 )
 
+// Ensure ImageServiceImpl implements ImageService
+var _ ImageService = (*ImageServiceImpl)(nil)
+
 // ImageServiceImpl handles AMI image operations with S3 storage
 type ImageServiceImpl struct {
 	config     *config.Config

hive/handlers/ec2/key/service_impl.go

@@ -27,6 +27,9 @@ import (
 	"github.com/mulgadc/hive/hive/utils"
 )
 
+// Ensure KeyServiceImpl implements KeyService
+var _ KeyService = (*KeyServiceImpl)(nil)
+
 // KeyServiceImpl handles key pair operations with ssh-keygen and S3 storage
 type KeyServiceImpl struct {
 	config     *config.Config

hive/handlers/ec2/snapshot/service_impl.go

@@ -16,6 +16,7 @@ import (
 	"github.com/mulgadc/hive/hive/awserrors"
 	"github.com/mulgadc/hive/hive/config"
 	"github.com/mulgadc/hive/hive/objectstore"
+	"github.com/mulgadc/hive/hive/utils"
 	"github.com/mulgadc/viperblock/viperblock"
 )
 
@@ -179,7 +180,7 @@ func (s *SnapshotServiceImpl) CreateSnapshot(input *ec2.CreateSnapshotInput) (*e
 	snapshotCfg := &SnapshotConfig{
 		SnapshotID:       snapshotID,
 		VolumeID:         volumeID,
-		VolumeSize:       int64(volumeConfig.VolumeMetadata.SizeGiB),
+		VolumeSize:       utils.SafeUint64ToInt64(volumeConfig.VolumeMetadata.SizeGiB),
 		State:            "completed",
 		Progress:         "100%",
 		StartTime:        now,

hive/handlers/ec2/volume/service_impl.go

@@ -27,6 +27,9 @@ import (
 
 const defaultGP3IOPS = 3000
 
+// Ensure VolumeServiceImpl implements VolumeService
+var _ VolumeService = (*VolumeServiceImpl)(nil)
+
 // VolumeServiceImpl handles EBS volume operations with S3 storage
 type VolumeServiceImpl struct {
 	config     *config.Config