Add tests for main package, manager, and various components

- Introduced unit tests for the main package to ensure compilation.
- Added tests for the manager, including validation of upload sessions and handling of Blender binary paths.
- Implemented tests for job token generation and validation, ensuring security and integrity.
- Created tests for configuration management and database schema to verify functionality.
- Added tests for logger and runner components to enhance overall test coverage and reliability.

internal/runner/blender/binary_test.go

@@ -0,0 +1,34 @@
+package blender
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestResolveBinaryPath_AbsoluteLikePath(t *testing.T) {
+	got, err := ResolveBinaryPath("./blender")
+	if err != nil {
+		t.Fatalf("ResolveBinaryPath failed: %v", err)
+	}
+	if !filepath.IsAbs(got) {
+		t.Fatalf("expected absolute path, got %q", got)
+	}
+}
+
+func TestResolveBinaryPath_Empty(t *testing.T) {
+	if _, err := ResolveBinaryPath(""); err == nil {
+		t.Fatal("expected error for empty blender binary")
+	}
+}
+
+func TestTarballEnv_SetsAndExtendsLDLibraryPath(t *testing.T) {
+	bin := filepath.Join(string(os.PathSeparator), "tmp", "blender", "blender")
+	got := TarballEnv(bin, []string{"A=B", "LD_LIBRARY_PATH=/old"})
+	joined := strings.Join(got, "\n")
+	if !strings.Contains(joined, "LD_LIBRARY_PATH=/tmp/blender/lib:/old") {
+		t.Fatalf("expected LD_LIBRARY_PATH to include blender lib, got %v", got)
+	}
+}
+