Imp in 64x64 when close, 32x32 at normal zoom; detailed sprites in their own texture

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

art/generated/imp-sprite/PROMPTS.md

@@ -108,3 +108,18 @@ The game copies `imp-32.png` and `imp-hack-32.png` to `assets/sprites/`.
 
 The gold sack is not generated: it is a small hand-made pixel pattern (`SACK_HD`, `SACK_SMALL`
 in `src/gfx.rs`) that the game places on every frame when the atlas is built.
+
+## 64x64 (2026-11-07)
+
+The high-res style shows the imp in 64x64 when close and in 32x32 at the normal zoom (both from
+the same raw sheets; a 64x64 sprite shown smaller would lose pixels and flicker). The 64x64
+sheets use the body scale 60 pixels, the feet row 63, 24 colours plus the iron greys:
+
+```bash
+python3 $T raw-1.png imp --views 5 --size 64 --colors 24 --crop 0,0.27,1,0.72 --step 9.217 --feet 63 \
+    --add-colors "150,152,168;104,106,122"
+# hack rows: --size 64 --step <body height>/60 --feet 63 --palette imp-64.png --outline-weight 0.6
+```
+
+Results: `imp-64.png`, `imp-hack-64.png`, preview `imp-hack-64-preview.png` (idle views in the
+right column). The game copies them to `assets/sprites/`.