Luxury Rigid Box Market Size & Forecasts 2026-2035, By Segments (Design Complexity, Material Type, End Use Industry, Box Type), Growth Opportunities, Innovation Landscape, Regulatory Shifts, Strategic Regional Insights (U.S., Japan, China, South Korea, UK, Germany, France), and Competitive Dynamics (WestRock, International Paper, Smurfit Kappa, DS Smith, Packaging Corporation of America)