chore(altair): add metadata for column-stratigraphic

Author: github-actions[bot]

plots/column-stratigraphic/metadata/altair.yaml

@@ -0,0 +1,19 @@
+# Per-library metadata for altair implementation of column-stratigraphic
+# Auto-generated by impl-generate.yml
+
+library: altair
+specification_id: column-stratigraphic
+created: '2026-03-15T22:59:28Z'
+updated: '2026-03-15T22:59:28Z'
+generated_by: claude-opus-4-5-20251101
+workflow_run: 23121198787
+issue: 4573
+python_version: 3.14.3
+library_version: 6.0.0
+preview_url: https://storage.googleapis.com/pyplots-images/plots/column-stratigraphic/altair/plot.png
+preview_thumb: https://storage.googleapis.com/pyplots-images/plots/column-stratigraphic/altair/plot_thumb.png
+preview_html: https://storage.googleapis.com/pyplots-images/plots/column-stratigraphic/altair/plot.html
+quality_score: null
+review:
+  strengths: []
+  weaknesses: []