Add new PNG images for clean and preview outputs

- Added `image_clean.png` to the output directory for the clean image representation.
- Added `image_clean_preview.png` for the preview of the clean image.
- Introduced `image_svg_clean.png` for the SVG clean image representation.

tools/vernon/json_to_png.py

@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+
+import argparse
+import json
+from pathlib import Path
+
+from PIL import Image
+
+
+def parse_args() -> argparse.Namespace:
+    parser = argparse.ArgumentParser(
+        description="Convert a JSON RGBA matrix back into a PNG image."
+    )
+    parser.add_argument("input_json", type=Path, help="Source JSON path")
+    parser.add_argument("output_png", type=Path, help="Destination PNG path")
+    return parser.parse_args()
+
+
+def load_matrix(json_path: Path) -> tuple[int, int, list[tuple[int, int, int, int]]]:
+    data = json.loads(json_path.read_text(encoding="utf-8"))
+    width = int(data["width"])
+    height = int(data["height"])
+    rows = data["pixels"]
+
+    if len(rows) != height:
+        raise ValueError(f"Expected {height} rows, found {len(rows)}")
+
+    flat_pixels: list[tuple[int, int, int, int]] = []
+    for row_index, row in enumerate(rows):
+        if len(row) != width:
+            raise ValueError(
+                f"Expected row {row_index} to contain {width} pixels, found {len(row)}"
+            )
+        for pixel in row:
+            if len(pixel) != 4:
+                raise ValueError("Each pixel must contain 4 RGBA channels")
+            flat_pixels.append(tuple(int(channel) for channel in pixel))
+
+    return width, height, flat_pixels
+
+
+def main() -> None:
+    args = parse_args()
+    width, height, pixels = load_matrix(args.input_json)
+    image = Image.new("RGBA", (width, height))
+    image.putdata(pixels)
+    args.output_png.parent.mkdir(parents=True, exist_ok=True)
+    image.save(args.output_png, format="PNG")
+    print(f"Wrote {args.output_png} with {width}x{height} RGBA pixels")
+
+
+if __name__ == "__main__":
+    main()