A vintage license plate becomes a miniature coastal road trip diorama

STATES:
  S0: input(COUNTRY, REGION, DECADE)
  S1: analyze_road_culture -> extract architectural styles, vehicle types, signage, landscape palettes, roadside business typology
  S2: gate_selection:
        - transportation gem (e.g., toll booth, ferry ramp)
        - leisure gem (e.g., scenic overlook, drive-in theater)
        - utilitarian gem (e.g., weigh station, rest stop)
        - whimsical/disappearing gem (e.g., giant muffler man, vanishing diner)
      ensure diverse environments (coastal, mountain, plain, desert, etc.)
  S3: for each gem, generate:
        - building geometry & materials
        - road type & plate-embossing map
        - 1-2 vehicles of the era
        - 2-3 traveler activities
        - weather & surface wear (plate rust, scratches)
        - 5 roadside props
        - label text
  S4: model license plate (period-correct shape, colors, embossing pattern) for the country & decade
  S5: per gem, repurpose embossing: raised letters become roads/curbs, borders become plate edges, numbers become parking spaces
  S6: assemble miniature diorama: place building, vehicles, travelers, props onto plate; apply weather wear
  S7: render each panel with 24mm lens, low cinematic angle, natural daylight, shallow DOF, slate-grey seamless bg
  S8: arrange 4 panels into 2x2 grid
  S9: final output image, no watermark