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/manager/blender_path.go

@@ -0,0 +1,35 @@
+package api
+
+import (
+	"fmt"
+	"os/exec"
+	"path/filepath"
+	"strings"
+)
+
+// resolveBlenderBinaryPath resolves a Blender executable to an absolute path.
+func resolveBlenderBinaryPath(blenderBinary string) (string, error) {
+	if blenderBinary == "" {
+		return "", fmt.Errorf("blender binary path is empty")
+	}
+
+	// Already contains a path component; normalize it.
+	if strings.Contains(blenderBinary, string(filepath.Separator)) {
+		absPath, err := filepath.Abs(blenderBinary)
+		if err != nil {
+			return "", fmt.Errorf("failed to resolve blender binary path %q: %w", blenderBinary, err)
+		}
+		return absPath, nil
+	}
+
+	// Bare executable name, resolve via PATH.
+	resolvedPath, err := exec.LookPath(blenderBinary)
+	if err != nil {
+		return "", fmt.Errorf("failed to locate blender binary %q in PATH: %w", blenderBinary, err)
+	}
+	absPath, err := filepath.Abs(resolvedPath)
+	if err != nil {
+		return "", fmt.Errorf("failed to resolve blender binary path %q: %w", resolvedPath, err)
+	}
+	return absPath, nil
+}