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.

pkg/blendfile/version_test.go

@@ -0,0 +1,96 @@
+package blendfile
+
+import (
+	"bytes"
+	"compress/gzip"
+	"testing"
+)
+
+func makeBlendHeader(major, minor int) []byte {
+	header := make([]byte, 12)
+	copy(header[:7], "BLENDER")
+	header[7] = '-'
+	header[8] = 'v'
+	header[9] = byte('0' + major)
+	header[10] = byte('0' + minor/10)
+	header[11] = byte('0' + minor%10)
+	return header
+}
+
+func TestParseVersionFromReader_Uncompressed(t *testing.T) {
+	tests := []struct {
+		name       string
+		major      int
+		minor      int
+		wantMajor  int
+		wantMinor  int
+	}{
+		{"Blender 4.02", 4, 2, 4, 2},
+		{"Blender 3.06", 3, 6, 3, 6},
+		{"Blender 2.79", 2, 79, 2, 79},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			header := makeBlendHeader(tt.major, tt.minor)
+			r := bytes.NewReader(header)
+
+			major, minor, err := ParseVersionFromReader(r)
+			if err != nil {
+				t.Fatalf("ParseVersionFromReader: %v", err)
+			}
+			if major != tt.wantMajor || minor != tt.wantMinor {
+				t.Errorf("got %d.%d, want %d.%d", major, minor, tt.wantMajor, tt.wantMinor)
+			}
+		})
+	}
+}
+
+func TestParseVersionFromReader_GzipCompressed(t *testing.T) {
+	header := makeBlendHeader(4, 2)
+	// Pad to ensure gzip has enough data for a full read
+	data := make([]byte, 128)
+	copy(data, header)
+
+	var buf bytes.Buffer
+	gz := gzip.NewWriter(&buf)
+	gz.Write(data)
+	gz.Close()
+
+	r := bytes.NewReader(buf.Bytes())
+	major, minor, err := ParseVersionFromReader(r)
+	if err != nil {
+		t.Fatalf("ParseVersionFromReader (gzip): %v", err)
+	}
+	if major != 4 || minor != 2 {
+		t.Errorf("got %d.%d, want 4.2", major, minor)
+	}
+}
+
+func TestParseVersionFromReader_InvalidMagic(t *testing.T) {
+	data := []byte("NOT_BLEND_DATA_HERE")
+	r := bytes.NewReader(data)
+
+	_, _, err := ParseVersionFromReader(r)
+	if err == nil {
+		t.Fatal("expected error for invalid magic, got nil")
+	}
+}
+
+func TestParseVersionFromReader_TooShort(t *testing.T) {
+	data := []byte("SHORT")
+	r := bytes.NewReader(data)
+
+	_, _, err := ParseVersionFromReader(r)
+	if err == nil {
+		t.Fatal("expected error for short data, got nil")
+	}
+}
+
+func TestVersionString(t *testing.T) {
+	got := VersionString(4, 2)
+	want := "4.2"
+	if got != want {
+		t.Errorf("VersionString(4, 2) = %q, want %q", got, want)
+	}
+}