TEST: chart render check
TEST PAGE. Synthetic data, not Cascade data. It checks whether inline SVG charts survive
publishing on this site. Delete after review.
TEST 1: bar chart, 12 bars with value labels
TEST 2: two-line chart, 24 points, labels at the line ends
TEST 3: text colour controls
If you can read this line but see no charts above, the site removed the SVG.