Hero 404 Quadrant Occlusion

A full-bleed 404 hero where the numerals and an orbiting occluding disc are rendered from one shared silhouette at half-cell precision using Unicode quadrant/half-block glyphs (▘▝▖▗▚▞▛▜▙▟█▀▄▌▐), so the disc's curved edge stays crisp instead of stair-stepping at one glyph per cell.