TODO: queue one-click JPEG export via direct canvas rasterizer

Current JPEG flow makes the user save a PDF, then re-pick it from
disk for PDF.js to convert. We can't cache the PDF in between
because window.print() doesn't expose the generated bytes to JS.

Log the proper fix: write a direct canvas rasterizer that walks
the layer model (image / text / shape / color / qr / pixelart),
draws each layer onto an off-screen canvas at the artboard's design
dims, then toBlob('image/jpeg'). Same approach the pixel-art PNG
export already uses, generalised across all layer types. CORS-
tainted remote images fall back to the existing PDF round-trip,
with a toast explaining why. ~300–500 LoC, no new dep.

Co-Authored-By: Claude Opus 4.7 <[email protected]>

TODO.md

@@ -22,6 +22,22 @@ Running list of deferred work. Detailed specs for the larger items live in
   flow currently renders the selected-layer dashed outline in the
   output. Add `body.exporting` (or similar) state that strips
   selection chrome before the raster snapshot.
+- **One-click JPEG export (skip the PDF round-trip).** Today the
+  flow is: print → user saves PDF → user re-picks PDF → PDF.js
+  converts to JPEG. We can't cache the PDF in between — `window
+  .print()` doesn't expose the generated bytes to JS. Instead,
+  write a direct canvas rasterizer that walks the layer model
+  (image / text / shape / color / qr / pixelart) and draws each
+  layer onto an off-screen canvas at the artboard's design dims,
+  then `toBlob('image/jpeg')`. Same approach the pixel-art PNG
+  export already uses, generalised. CORS-tainted remote images
+  (cross-origin host without `Access-Control-Allow-Origin`) would
+  break the direct path — fall back to the existing PDF round-trip
+  for those with a one-line "this image needs the PDF route" toast.
+  Most modern image hosts (CDNs, Blossom blobs) send CORS so the
+  fallback should be rare. ~300–500 LoC of layer-by-layer drawing
+  code; reuses `renderShapeIntoElement` etc. as references for
+  geometry but writes to canvas instead of DOM.
 - **Independent-axis corner-node resize.** Corner resize handles
   currently lock the aspect ratio (or scale both axes together).
   Behaviour should follow the actual drag vector: dragging mostly