Bright streaks move when we present the part differently

@ImranArcher0392 Some labels came from the pictures alone. We still have the samples, but those labels aren't tied to physical inspection results. That's irritatingly circular.

Keep the image-only labels uncertain pending physical inspection. A controlled comparison of lighting and presentation can then investigate whether the moving streaks indicate reflection effects.

@ImranArcher0392 A scratch's visibility can change with presentation too. Don't let 'moving streak' quietly become the rule for relabelling something acceptable.

You're right to qualify that. The streak behaviour motivates an imaging investigation; it doesn't replace physical classification under the agreed inspection procedure.

@ImranArcher0392 The reference problem is clearer, but I still can't judge inspection performance from our example images. The physical labels and image comparisons need more work.

The remaining physical-label and comparison work explains the open judgement. Clearer uncertainty doesn't yet establish inspection performance.