Create a realistic procedural medieval dungeon kit. Include modular elements such as stone walls, floors, archways, doors, and pillars. All pieces should have rough, uneven stones with cracks, wear, subtle moss, and damp stains. Textures must be high-detail, tileable, and consistent across modules. Emphasize a dark, cold, and decrepit atmosphere, suitable for building varied dungeon layouts while maintaining realism and cohesion.