feat: impl files endpoints

apps/backend/internal/virtualfs/file_content.go

@@ -0,0 +1,34 @@
+package virtualfs
+
+import (
+	"io"
+
+	"github.com/get-drexa/drexa/internal/blob"
+)
+
+type FileContent struct {
+	Size    int64
+	Reader  io.ReadCloser
+	BlobKey blob.Key
+	URL     string
+}
+
+func EmptyFileContent() FileContent {
+	return FileContent{}
+}
+
+func FileContentFromReader(reader io.Reader) FileContent {
+	return FileContent{Reader: io.NopCloser(reader)}
+}
+
+func FileContentFromReaderWithSize(reader io.Reader, size int64) FileContent {
+	return FileContent{Reader: io.NopCloser(reader), Size: size}
+}
+
+func FileContentFromBlobKey(blobKey blob.Key) FileContent {
+	return FileContent{BlobKey: blobKey}
+}
+
+func FileContentFromURL(url string) FileContent {
+	return FileContent{URL: url}
+}