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_test.go

@@ -0,0 +1,27 @@
+package api
+
+import (
+	"testing"
+	"time"
+)
+
+func TestGetLatestBlenderForMajorMinor_UsesCachedVersions(t *testing.T) {
+	blenderVersionCache.mu.Lock()
+	blenderVersionCache.versions = []BlenderVersion{
+		{Major: 4, Minor: 2, Patch: 1, Full: "4.2.1"},
+		{Major: 4, Minor: 2, Patch: 3, Full: "4.2.3"},
+		{Major: 4, Minor: 1, Patch: 9, Full: "4.1.9"},
+	}
+	blenderVersionCache.fetchedAt = time.Now()
+	blenderVersionCache.mu.Unlock()
+
+	m := &Manager{}
+	v, err := m.GetLatestBlenderForMajorMinor(4, 2)
+	if err != nil {
+		t.Fatalf("GetLatestBlenderForMajorMinor failed: %v", err)
+	}
+	if v.Full != "4.2.3" {
+		t.Fatalf("expected highest patch, got %+v", *v)
+	}
+}
+