fix: replace nil context with context.TODO

internal/observability/helpers_test.go

@@ -0,0 +1,35 @@
+package observability
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"testing"
+)
+
+func TestWarnEnrichesSourceAndErrorContext(t *testing.T) {
+	fields := enrichFields(LogLevelWarn, map[string]any{"anime_id": 123}, wrappedError())
+
+	if fields["anime_id"] != 123 {
+		t.Fatalf("expected existing field to survive, got %#v", fields["anime_id"])
+	}
+
+	source, ok := fields["source"].(string)
+	if !ok || source == "" {
+		t.Fatalf("expected source field, got %#v", fields["source"])
+	}
+
+	errorType, ok := fields["error_type"].(string)
+	if !ok || errorType == "" {
+		t.Fatalf("expected error_type field, got %#v", fields["error_type"])
+	}
+
+	chain, ok := fields["error_chain"].(string)
+	if !ok || !strings.Contains(chain, "query anime") || !strings.Contains(chain, "db timeout") {
+		t.Fatalf("expected wrapped error chain, got %#v", fields["error_chain"])
+	}
+}
+
+func wrappedError() error {
+	return fmt.Errorf("query anime: %w", errors.New("db timeout"))
+}