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/runner/workspace/archive_test.go

@@ -0,0 +1,101 @@
+package workspace
+
+import (
+	"archive/tar"
+	"bytes"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func createTarBuffer(files map[string]string) *bytes.Buffer {
+	var buf bytes.Buffer
+	tw := tar.NewWriter(&buf)
+	for name, content := range files {
+		hdr := &tar.Header{
+			Name: name,
+			Mode: 0644,
+			Size: int64(len(content)),
+		}
+		tw.WriteHeader(hdr)
+		tw.Write([]byte(content))
+	}
+	tw.Close()
+	return &buf
+}
+
+func TestExtractTar(t *testing.T) {
+	destDir := t.TempDir()
+
+	buf := createTarBuffer(map[string]string{
+		"hello.txt": "world",
+		"sub/a.txt": "nested",
+	})
+
+	if err := ExtractTar(buf, destDir); err != nil {
+		t.Fatalf("ExtractTar: %v", err)
+	}
+
+	data, err := os.ReadFile(filepath.Join(destDir, "hello.txt"))
+	if err != nil {
+		t.Fatalf("read hello.txt: %v", err)
+	}
+	if string(data) != "world" {
+		t.Errorf("hello.txt = %q, want %q", data, "world")
+	}
+
+	data, err = os.ReadFile(filepath.Join(destDir, "sub", "a.txt"))
+	if err != nil {
+		t.Fatalf("read sub/a.txt: %v", err)
+	}
+	if string(data) != "nested" {
+		t.Errorf("sub/a.txt = %q, want %q", data, "nested")
+	}
+}
+
+func TestExtractTarStripPrefix(t *testing.T) {
+	destDir := t.TempDir()
+
+	buf := createTarBuffer(map[string]string{
+		"toplevel/":        "",
+		"toplevel/foo.txt": "bar",
+	})
+
+	if err := ExtractTarStripPrefix(buf, destDir); err != nil {
+		t.Fatalf("ExtractTarStripPrefix: %v", err)
+	}
+
+	data, err := os.ReadFile(filepath.Join(destDir, "foo.txt"))
+	if err != nil {
+		t.Fatalf("read foo.txt: %v", err)
+	}
+	if string(data) != "bar" {
+		t.Errorf("foo.txt = %q, want %q", data, "bar")
+	}
+}
+
+func TestExtractTarStripPrefix_PathTraversal(t *testing.T) {
+	destDir := t.TempDir()
+
+	buf := createTarBuffer(map[string]string{
+		"prefix/../../../etc/passwd": "pwned",
+	})
+
+	err := ExtractTarStripPrefix(buf, destDir)
+	if err == nil {
+		t.Fatal("expected error for path traversal, got nil")
+	}
+}
+
+func TestExtractTar_PathTraversal(t *testing.T) {
+	destDir := t.TempDir()
+
+	buf := createTarBuffer(map[string]string{
+		"../../../etc/passwd": "pwned",
+	})
+
+	err := ExtractTar(buf, destDir)
+	if err == nil {
+		t.Fatal("expected error for path traversal, got nil")
+	}
+}