Fix demo rendering and baseline requirements

Makefile

@@ -1,4 +1,4 @@
-.PHONY: setup install install-dev install-gpu test test-contracts lint clean preflight demo
+.PHONY: setup install install-dev install-gpu test test-contracts lint clean preflight demo demo-list
 
 # ---- One-command setup ----
 
@@ -47,10 +47,10 @@ demo:
 	@echo "==> Rendering zero-key demo videos (no API keys needed)..."
 	@echo "    These use only Remotion components — animated charts, text, data viz."
 	@echo ""
-	./render-demo.sh
+	python render_demo.py
 
 demo-list:
-	@./render-demo.sh --list
+	@python render_demo.py --list
 
 lint:
 	python -m py_compile tools/base_tool.py