docs: document deterministic multi-family SVG rendering

Author: ProfRandom92

docs/benchmarks/multi_family_admissibility_benchmark.md

@@ -65,6 +65,17 @@ python scripts/generate_multi_family_admissibility_artifact.py
 npm run generate:multi-family-admissibility
 ```
 
+## Deterministic SVG rendering
+
+The benchmark also includes a deterministic SVG rendering step:
+
+- Input: `artifacts/multi_family_admissibility_results.json`
+- Output: `artifacts/multi_family_admissibility_curves.svg`
+- Script: `scripts/render_multi_family_admissibility_svg.py`
+- npm command: `npm run generate:multi-family-svg`
+
+The SVG output is deterministic by design with fixed dimensions, fixed axes, fixed degradation level order, lexicographic family order, a hardcoded palette, no timestamps, no generated IDs, and no embedded JavaScript.
+
 ## Validation commands
 
 Run the targeted protections plus the repository-wide check entrypoint:
@@ -73,6 +84,7 @@ Run the targeted protections plus the repository-wide check entrypoint:
 pytest tests/test_multi_family_admissibility_artifact.py -q
 pytest tests/test_artifact_reproducibility.py -q
 pytest tests/test_manifest_fixture_families.py -q
+pytest tests/test_multi_family_svg_renderer.py -q
 npm run check
 ```