Bump output resolution to 1280 via MAX_OUTPUT_DIM constant

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app.py

@@ -15,6 +15,7 @@ from PIL import Image
 
 MAX_SEED = np.iinfo(np.int32).max
 LANCZOS = getattr(Image, "Resampling", Image).LANCZOS
+MAX_OUTPUT_DIM = 1280
 
 device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
 
@@ -176,13 +177,13 @@ def b64_to_pil_list(b64_json_str):
 
 def update_dimensions_on_upload(image):
     if image is None:
-        return 1024, 1024
+        return MAX_OUTPUT_DIM, MAX_OUTPUT_DIM
     w, h = image.size
     if w > h:
-        nw = 1024
+        nw = MAX_OUTPUT_DIM
         nh = int(nw * h / w)
     else:
-        nh = 1024
+        nh = MAX_OUTPUT_DIM
         nw = int(nh * w / h)
     return (nw // 8) * 8, (nh // 8) * 8