refactor: Move recipe generator to cook/ directory and fix flattening bugs

- Move recipe-generator/ to cook/ for cleaner structure

- Fix ksflatten-relative path conversion to handle all %include paths

- Fix validation exit code to only fail on actual errors

- All recipes now generate and flatten successfully via make all

cook/Makefile

@@ -0,0 +1,41 @@
+.PHONY: help generate-recipes validate-recipes clean clean-dishes install-deps flatten-dishes all
+
+help:
+	@echo "Phyllome OS Recipe Generator"
+	@echo ""
+	@echo "Available targets:"
+	@echo "  generate-recipes  - Generate all recipes from manifest"
+	@echo "  validate-recipes  - Validate existing recipes"
+	@echo "  all               - Generate, validate, and flatten all recipes (default)"
+	@echo "  flatten-dishes    - Flatten all recipes to dishes"
+	@echo "  clean-dishes      - Remove flattened dishes"
+	@echo "  clean             - Remove generated recipes"
+	@echo "  install-deps      - Install Python dependencies"
+
+all: generate-recipes validate-recipes flatten-dishes
+	@echo "✓ All recipes generated, validated, and flattened to dishes"
+
+install-deps:
+	pip install -r requirements.txt
+
+generate-recipes:
+	rm -f recipes/*.cfg
+	python3 generate_recipe.py \
+		--manifest recipes_manifest.yaml \
+		--output-dir recipes/
+
+validate-recipes:
+	python3 generate_recipe.py \
+		--validate recipes/*.cfg
+
+flatten-dishes:
+	@echo "Flattening recipes to dishes..."
+	@python bin/ksflatten-relative recipes dishes
+
+clean-dishes:
+	rm -f dishes/*.cfg
+	@echo "✓ Flattened dishes removed. Run 'make flatten-dishes' to regenerate."
+
+clean:
+	rm -f recipes/*.cfg
+	@echo "Generated recipes removed. Edit recipes_manifest.yaml and run 'make generate-recipes' to regenerate. Run 'make clean-dishes' to remove flattened dishes."