feat(age): support /dev/stdin

Signed-off-by: Caio Rocha de Oliveira <caiorocoli@gmail.com>

Author: Dexmachi

age/keysource.go

@@ -420,7 +420,7 @@ func ClearFileStreamCache() {
 // reads a file from the given path, if it is a stream (e.g., /dev/fd/* or /proc/*)
 // it caches the content in memory to avoid issues with multiple reads from the same stream.
 func readStreamSafe(path string) ([]byte, error) {
-	isStream := strings.HasPrefix(path, "/dev/fd/") || strings.HasPrefix(path, "/proc/")
+	isStream := strings.HasPrefix(path, "/dev/fd/") || strings.HasPrefix(path, "/proc/") || strings.HasPrefix(path, "/dev/stdin")
 
 	if isStream {
 		if cached, ok := fileStreamCache.Load(path); ok {