feat: expand and fix issues in SVG renderer

tests/Makefile

@@ -2,17 +2,22 @@ CXX ?= g++
 CXXFLAGS ?= -std=c++20 -O2 -Wall -Wextra
 
 HTTP_TEST := http_test
+SVG_TEST := svg_renderer_test
 
 .PHONY: all check clean
 
-all: $(HTTP_TEST)
+all: $(HTTP_TEST) $(SVG_TEST)
 
 $(HTTP_TEST): http_test.cpp
 	$(CXX) $(CXXFLAGS) -I../programs/include \
 		-I../programs/lib/bearssl/inc $< -o $@
 
-check: $(HTTP_TEST)
+$(SVG_TEST): svg_renderer_test.cpp ../programs/include/gui/svg.hpp
+	$(CXX) $(CXXFLAGS) -I../programs/include $< -o $@
+
+check: $(HTTP_TEST) $(SVG_TEST)
 	./$(HTTP_TEST)
+	./$(SVG_TEST)
 
 clean:
-	rm -f $(HTTP_TEST)
+	rm -f $(HTTP_TEST) $(SVG_TEST)