refactor: clean up code and enhance utilities with new functions

internal/utils/strutils/filepath.go

@@ -0,0 +1,11 @@
+package strutils
+
+import "strings"
+
+// IsValidFilename checks if a filename is safe and doesn't contain path traversal attempts
+// Returns true if the filename is valid, false otherwise
+func IsValidFilename(filename string) bool {
+	return !strings.Contains(filename, "/") &&
+		!strings.Contains(filename, "\\") &&
+		!strings.Contains(filename, "..")
+}