dithered_perceptual_gradients_export_as_images_with_noise_on_the_fill
compares two exports byte for byte: a stroke's file with dither and
without. The export dates a file by the clock, in whole seconds
(metadata::output_time, unless SOURCE_DATE_EPOCH is set), and the
tests' `uncompressed` helper gave no date of its own. So the test
failed whenever a second ticked between the two exports: the files
then differed in /CreationDate, /ModDate, the XMP dates and the IDs
made from them, and in nothing else. CI hit it on #3807.
With the wall clock moved a second on each read (an LD_PRELOAD shim
on clock_gettime), the test failed 5 runs of 5, and it was the only
one of vectorcraft-pdf's 380 tests that did. With the helper's date
fixed it passes, as do the other 379.
The helper now dates its exports `created: Some(0)`, as the crate's
other tests that compare whole files do (tests_editing, tests_pdf13,
tests_webview).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HhvnnnD5fTFupK8WWq35un
