Add tests for outline_color in render_labels

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: timtreis

tests/pl/test_render_labels.py

@@ -96,6 +96,12 @@ def test_plot_can_color_by_hex_with_alpha(self, sdata_blobs: SpatialData):
     def test_plot_alpha_overwrites_opacity_from_color(self, sdata_blobs: SpatialData):
         sdata_blobs.pl.render_labels("blobs_labels", color=[0.5, 0.5, 1.0, 0.5], fill_alpha=1.0).pl.show()
 
+    def test_plot_can_render_outline_color(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_labels("blobs_labels", outline_alpha=1, fill_alpha=0, outline_color="red").pl.show()
+
+    def test_plot_can_render_outline_with_fill(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_labels("blobs_labels", outline_alpha=1, fill_alpha=0.3, outline_color="white").pl.show()
+
     def test_plot_can_color_labels_by_continuous_variable(self, sdata_blobs: SpatialData):
         sdata_blobs.pl.render_labels("blobs_labels", color="channel_0_sum").pl.show()