refactor: Inject mtio package to allow for remote implementation

pkg/fs/filesystem.go

@@ -241,6 +241,7 @@ func (f *STFS) Initialize(rootProposal string, rootPerm os.FileMode) (root strin
 
 		if err := recovery.Index(
 			reader,
+			f.readOps.GetBackend().MagneticTapeIO,
 			f.readOps.GetMetadata(),
 			f.readOps.GetPipes(),
 			f.readOps.GetCrypto(),

pkg/fs/filesystem_test.go

@@ -21,6 +21,7 @@ import (
 	"github.com/pojntfx/stfs/pkg/cache"
 	"github.com/pojntfx/stfs/pkg/config"
 	"github.com/pojntfx/stfs/pkg/keys"
+	"github.com/pojntfx/stfs/pkg/mtio"
 	"github.com/pojntfx/stfs/pkg/operations"
 	"github.com/pojntfx/stfs/pkg/persisters"
 	"github.com/pojntfx/stfs/pkg/tape"
@@ -339,8 +340,10 @@ func createSTFS(
 
 	initialize bool,
 ) (afero.Fs, error) {
+	mt := mtio.MagneticTapeIO{}
 	tm := tape.NewTapeManager(
 		drive,
+		mt,
 		recordSize,
 		false,
 	)
@@ -369,6 +372,8 @@ func createSTFS(
 
 		GetReader:   tm.GetReader,
 		CloseReader: tm.Close,
+
+		MagneticTapeIO: mt,
 	}
 	readCryptoConfig := config.CryptoConfig{
 		Recipient: signatureRecipient,