CURTAIN PLATES, DAY  ->  src/assets/curtains/<room>-day.webp
Sizes: 1200 x 896 (4:3 landscape windows), 1264 x 848 (3:2), 896 x 1200 (3:4 tall windows).
The plate is the room's window wall seen from inside; the app draws the real curtains/sheers over it in 3D.
Input: a photo of the window from inside the room (or a render of it), four rooms per sheet if they share a format.

Redraw this reference sheet of four window views as four architect's alcohol-marker renderings on one sheet of white
marker paper. Keep the sheet layout exactly: the same 2x2 grid of four panels in the same places, with the same clean
white gutters between them. Inside every panel keep the exact composition of the reference: the window frames and
mullions, the walls, sills and floor inside the room, and the view outside - garden, trees, roofs, distant buildings
and sky - all stay exactly where they are. {MARKER STYLE - Exterior, but:} layered cool-grey and warm-grey marker tones
for the interior walls and shadows, a soft blue daylight sky laid in with horizontal marker sweeps. Calm daylight.

Then: python3 tools/pictools.py split sheet.png src/assets/curtains 1200 896 dining-day,salon-day,study-day,tatami-day
      python3 tools/pictools.py thumb src/assets/curtains/dining-day.webp src/assets/curtain-thumbs/dining.webp
