Use full-bleed photos with a single-line bottom watermark

tests/test_photo_captions.py

@@ -46,7 +46,7 @@ def test_child_folder_inherits_date_and_location():
 
 
 @pytest.mark.parametrize("profile", ["color", "grayscale"])
-def test_native_caption_layout_has_three_separate_lines(service, profile):
+def test_native_caption_layout_has_single_watermark_line(service, profile):
     out = BytesIO()
     Image.new("RGB", (1600, 900), "blue").save(out, "JPEG")
     result = render_captioned_photo(
@@ -57,9 +57,9 @@ def test_native_caption_layout_has_three_separate_lines(service, profile):
     )
     with Image.open(BytesIO(result)) as image:
         assert image.size == (1200, 1600)
-        for y in [1320, 1410, 1480]:
-            darkest = image.crop((50, y, 1150, y + 65)).convert("L").getextrema()[0]
-            assert darkest < 50, "Caption row is missing"
+        assert image.crop((30, 1528, 1170, 1600)).convert("L").getextrema()[0] < 50
+        assert image.getpixel((20, 1500))[0] < 230
+        assert image.getpixel((20, 1590))[0] > 240
         pixel = image.getpixel((600, 640))
         assert (
             len(set(pixel)) <= 2