Per-case visuals, incident vignettes, guided play, no-repeat dealing, four new crime kinds (#4)

fix: restore the #3 UI overhaul that a metadata push accidentally overwrote

docs: reference Supertone/supertonic-3 in Space model metadata and credits

UI overhaul: mobile corkboard, Connect the Dots, nav and overflow fixes (#3)

feat: multi-crime cases, scene+exhibit pixel art, background AI generation

Case Zero - initial public release (fully local: Qwen2.5-1.5B via llama.cpp + Supertonic, custom pixel-noir SPA via gradio.Server)