chore(altair): add metadata for bar-3d-categorical

Author: github-actions[bot]

plots/bar-3d-categorical/metadata/python/altair.yaml

@@ -0,0 +1,21 @@
+# Per-library metadata for altair implementation of bar-3d-categorical
+# Auto-generated by impl-generate.yml
+
+library: altair
+language: python
+specification_id: bar-3d-categorical
+created: '2026-05-15T08:51:41Z'
+updated: '2026-05-15T08:51:41Z'
+generated_by: claude-sonnet
+workflow_run: 25908295059
+issue: 5248
+python_version: 3.13.13
+library_version: 6.1.0
+preview_url_light: https://storage.googleapis.com/anyplot-images/plots/bar-3d-categorical/python/altair/plot-light.png
+preview_url_dark: https://storage.googleapis.com/anyplot-images/plots/bar-3d-categorical/python/altair/plot-dark.png
+preview_html_light: https://storage.googleapis.com/anyplot-images/plots/bar-3d-categorical/python/altair/plot-light.html
+preview_html_dark: https://storage.googleapis.com/anyplot-images/plots/bar-3d-categorical/python/altair/plot-dark.html
+quality_score: null
+review:
+  strengths: []
+  weaknesses: []