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/runner_test.go

@@ -0,0 +1,40 @@
+package runner
+
+import (
+	"encoding/hex"
+	"testing"
+)
+
+func TestNewRunner_InitializesFields(t *testing.T) {
+	r := New("http://localhost:8080", "runner-a", "host-a", false)
+	if r == nil {
+		t.Fatal("New should return a runner")
+	}
+	if r.name != "runner-a" || r.hostname != "host-a" {
+		t.Fatalf("unexpected runner identity: %q %q", r.name, r.hostname)
+	}
+}
+
+func TestRunner_GPUFlagsSetters(t *testing.T) {
+	r := New("http://localhost:8080", "runner-a", "host-a", false)
+	r.SetGPULockedOut(true)
+	if !r.IsGPULockedOut() {
+		t.Fatal("expected GPU lockout to be true")
+	}
+}
+
+func TestGenerateFingerprint_PopulatesValue(t *testing.T) {
+	r := New("http://localhost:8080", "runner-a", "host-a", false)
+	r.generateFingerprint()
+	fp := r.GetFingerprint()
+	if fp == "" {
+		t.Fatal("fingerprint should not be empty")
+	}
+	if len(fp) != 64 {
+		t.Fatalf("fingerprint should be sha256 hex, got %q", fp)
+	}
+	if _, err := hex.DecodeString(fp); err != nil {
+		t.Fatalf("fingerprint should be valid hex: %v", err)
+	}
+}
+