Fix legend border artifact in ppc_freqpoly

[utkarshpawade]

Fixes #134

• ppc_freqpoly() and ppc_freqpoly_grouped() displayed a visible dark border around the y legend key due to the color aesthetic from geom_area() bleeding into the legend glyph
• Added guides(fill = guide_legend(override.aes = list(color = NA))) to suppress the outline color in legend keys

Before

After

[Copilot]

Pull request overview

This PR fixes a ggplot2 legend rendering artifact in the posterior predictive check frequency polygon plots (ppc_freqpoly() and, transitively, ppc_freqpoly_grouped()), where the geom_area() outline color was bleeding into the legend key.

Changes:

• Add a guides(fill = guide_legend(override.aes = list(color = NA))) override to suppress the outline color in the fill legend key for ppc_freqpoly().
• Document the fix in NEWS.md.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
R/ppc-distributions.R	Overrides legend aesthetics for the fill guide to remove the unwanted border artifact in freqpoly PPC plots (also affects grouped variant via delegation).
NEWS.md	Adds a changelog entry describing the legend border artifact fix.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.15%. Comparing base (44c3e5c) to head (4a4e176).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #537   +/-   ##
=======================================
  Coverage   99.15%   99.15%           
=======================================
  Files          35       35           
  Lines        5920     5921    +1     
=======================================
+ Hits         5870     5871    +1     
  Misses         50       50           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.