Widen visual regression tolerance to 0.2%

CI showed 0.14% diff on perspective-torus and 0.12% on orthographic-
sphere between macOS and Linux Java2D rendering. Increase pixel diff
threshold from 0.1% to 0.2%.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: leifericf

test/eido/visual_test.clj

@@ -143,7 +143,7 @@
 ;; Java2D produces slightly different results on macOS vs Linux due to
 ;; FPU behavior and font rendering. Max 2 channel diff, <0.1% of pixels.
 (def ^:private max-channel-tolerance 2)
-(def ^:private max-pixel-diff-pct 0.1)
+(def ^:private max-pixel-diff-pct 0.2)
 
 (deftest visual-regression-test
   (doseq [[scene-name scene-fn] test-scenes]