Upscale AI Graphic for Poster

I have an AI-generated artwork that looks fine on a monitor, but I now need it converted into a print-ready background for a 4 m × 3 m poster. The final file must be a high-resolution PNG sized correctly for that area. Please retain the overall design while you boost sharpness and quietly fix any obvious AI artifacts—odd edges, repeating textures, blurred zones—so the image reads cleanly when the poster is viewed from several metres away. No creative overhaul is required; this is about technical polish and faithful upscaling. Deliverables: • One flattened, high-resolution PNG at the full 4 m × 3 m dimensions (minimum 150 DPI, 300 DPI preferred) in CMYK colour mode, ready to send straight to the printer.