Refactor runner and installation scripts for improved functionality

- Removed the `--disable-hiprt` flag from the runner command, simplifying the rendering options for users.
- Updated the `jiggablend-runner` script and README to reflect the removal of the HIPRT control flag, enhancing clarity in usage instructions.
- Enhanced the installation script to provide clearer examples for running the jiggablend manager and runner, improving user experience during setup.
- Implemented a more robust GPU backend detection mechanism, allowing for better compatibility with various hardware configurations.

internal/storage/storage.go

@@ -82,6 +82,9 @@ func (s *Storage) JobPath(jobID int64) string {
 
 // SaveUpload saves an uploaded file
 func (s *Storage) SaveUpload(jobID int64, filename string, reader io.Reader) (string, error) {
+	// Sanitize filename to prevent path traversal
+	filename = filepath.Base(filename)
+
 	jobPath := s.JobPath(jobID)
 	if err := os.MkdirAll(jobPath, 0755); err != nil {
 		return "", fmt.Errorf("failed to create job directory: %w", err)