Fix Unicode encoding error: replace Δ with Delta

pdf_comparator.py

@@ -292,7 +292,7 @@ def draw_cmyk_panel(base: Image.Image, entries, title: str = 'CMYK breakdowns',
         d.text((x0, y), f"#{idx}", fill=(0,0,0)); y += 14
         d.text((x0, y), f"A: C {aC}% M {aM}% Y {aY}% K {aK}%", fill=(0,0,0)); y += 14
         d.text((x0, y), f"B: C {bC}% M {bM}% Y {bY}% K {bK}%", fill=(0,0,0)); y += 14
-        d.text((x0, y), f"Δ: C {dC}% M {dM}% Y {dY}% K {dK}%", fill=(120,0,0)); y += 18
+        d.text((x0, y), f"Delta: C {dC}% M {dM}% Y {dY}% K {dK}%", fill=(120,0,0)); y += 18
         if y > h - 40: break
     return out