chore: move some types to model

internal/model/stream.go

@@ -0,0 +1,15 @@
+package model
+
+import (
+	"io"
+)
+
+type FileStream struct {
+	FileInfo
+	io.ReadCloser
+	Mimetype string
+}
+
+func (f FileStream) GetMimetype() string {
+	return f.Mimetype
+}