feat: scaffold go vehicle gateway core

go/vehicle-gateway/internal/observability/logger.go

@@ -0,0 +1,13 @@
+package observability
+
+import (
+	"log/slog"
+	"os"
+)
+
+// NewLogger returns a JSON logger with a stable service field so ECS logs from
+// different Go processes can be filtered without relying on container names.
+func NewLogger(service string) *slog.Logger {
+	handler := slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{AddSource: true})
+	return slog.New(handler).With("service", service)
+}