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.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"strings"
 
@@ -44,8 +45,12 @@ func (m *Manager) GetBinaryPath(version string) (string, error) {
 		if binaryInfo, err := os.Stat(binaryPath); err == nil {
 			// Verify it's actually a file (not a directory)
 			if !binaryInfo.IsDir() {
-				log.Printf("Found existing Blender %s installation at %s", version, binaryPath)
-				return binaryPath, nil
+				absBinaryPath, err := ResolveBinaryPath(binaryPath)
+				if err != nil {
+					return "", err
+				}
+				log.Printf("Found existing Blender %s installation at %s", version, absBinaryPath)
+				return absBinaryPath, nil
 			}
 		}
 		// Version folder exists but binary is missing - might be incomplete installation
@@ -72,20 +77,50 @@ func (m *Manager) GetBinaryPath(version string) (string, error) {
 		return "", fmt.Errorf("blender binary not found after extraction")
 	}
 
-	log.Printf("Blender %s installed at %s", version, binaryPath)
-	return binaryPath, nil
+	absBinaryPath, err := ResolveBinaryPath(binaryPath)
+	if err != nil {
+		return "", err
+	}
+
+	log.Printf("Blender %s installed at %s", version, absBinaryPath)
+	return absBinaryPath, nil
 }
 
 // GetBinaryForJob returns the Blender binary path for a job.
 // Uses the version from metadata or falls back to system blender.
 func (m *Manager) GetBinaryForJob(version string) (string, error) {
 	if version == "" {
-		return "blender", nil // System blender
+		return ResolveBinaryPath("blender")
 	}
 
 	return m.GetBinaryPath(version)
 }
 
+// ResolveBinaryPath resolves a Blender executable to an absolute path.
+func ResolveBinaryPath(blenderBinary string) (string, error) {
+	if blenderBinary == "" {
+		return "", fmt.Errorf("blender binary path is empty")
+	}
+
+	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
+	}
+
+	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
+}
+
 // TarballEnv returns a copy of baseEnv with LD_LIBRARY_PATH set so that a
 // tarball Blender installation can find its bundled libs (e.g. lib/python3.x).
 // If blenderBinary is the system "blender" or has no path component, baseEnv is