Enhance run setup to support three game modes (Alone, Naked and Afraid, Naked and Afraid XL), with scenario availability filtered by selected mode. Add a dedicated scenario selection screen with a highlighted left-side list and a larger right-side detail pane containing description, daunting notes, and motivation text. Extend scenario metadata with SupportedModes and narrative fields, migrate built-ins to include mode mappings and richer descriptions, and update validations/tests to enforce mode coverage and narrative completeness.