Silo: pixel-art version for the pixel look

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/PROJECT_MAP.md

@@ -341,9 +341,9 @@ drawWorld: the per-grain pixel buffer (pixel look), also the input of the smooth
 - functions: drawWorld
 - variables: TUBE_CLASS
 
-### src/render/machines.js (157 lines)
+### src/render/machines.js (197 lines)
 Machine overlays: fans, engines, refiner, cutter, silo and the rest, drawn on top of the world.
-- functions: cellRect, drawHazardRims, drawMachines, drawSilo
+- functions: cellRect, drawHazardRims, drawMachines, drawSilo, drawSiloPixel
 
 ### src/render/overlays.js (228 lines)
 Other overlays: floating text, rain and snow, flow arrows, filter tags, molds, the bot, particles.
@@ -470,4 +470,5 @@ The frame loop and boot.
 - `tools/scenes/belt-heap.js`: A belt feeding an upward screw: sand underneath a deep heap of copper ore. Run clear-sky.js first, e.g. python3 tools/shot.py /tmp/belt-heap.png --setup tools/scenes/clear-sky.js --js "$(cat tools/scenes/belt-heap.js)" --ticks 240 --zoom 7
 - `tools/scenes/clear-sky.js`: A clear work area left of the bot's starting point (the trade dock is to its right): open sky 160 grains wide and 40 tall, over a flat stone floor. Money and a bag of building stuff to build with. Sets FLOOR (the first row of the floor), BX, BY (the leftmost block of the area that stands on the floor) and CAM (the middle of the area).
 - `tools/scenes/mold-labels.js`: Run after clear-sky.js: filling, blocked, set, and hot machinery in one view.
+- `tools/scenes/silo.js`: Run after clear-sky.js; leave paused so the open gate keeps its demonstration charge.
 - `tools/scenes/stone-uses.js`: The stone and sand machines: a half-full silo with its gate open over a belt, a stone cutter fed with rubble, and cut stone and glass brick walls. Run clear-sky.js first, e.g. python3 tools/shot.py /tmp/stone.png --setup tools/scenes/clear-sky.js --js "$(cat tools/scenes/stone-uses.js)" --ticks 240 --zoom 7