feat: add standalone client with FIFO command interface

Makefile

@@ -0,0 +1,22 @@
+# Top‑level Makefile – delegates build/clean/test to subdirectories
+
+SUBDIRS = engine client
+
+.PHONY: all build clean test $(SUBDIRS)
+
+all: build
+
+build: $(SUBDIRS)
+	@echo "Build complete."
+
+$(SUBDIRS):
+	$(MAKE) -C $@
+
+test:
+	$(MAKE) -C engine test
+
+clean:
+	@for dir in $(SUBDIRS); do \
+	    echo "Cleaning $$dir..."; \
+	    $(MAKE) -C $$dir clean; \
+	done