feat: add clean target to remove build artifacts

Added clean target that removes the binary, program.out, and profile directory.

Makefile

@@ -1,7 +1,7 @@
 BINARY_NAME=lambda
 TEST=simple
 
-.PHONY: help build run profile explain graph docs
+.PHONY: help build run profile explain graph docs clean
 .DEFAULT_GOAL := help
 .SILENT:
 
@@ -13,6 +13,7 @@ help:
 	echo "  explain  - Build and run with explanation mode and profiling"
 	echo "  graph    - Generate and open CPU profile visualization"
 	echo "  docs     - Start local godoc server on port 6060"
+	echo "  clean    - Remove all build artifacts"
 
 build:
 	go build -o ${BINARY_NAME} ./cmd/lambda
@@ -35,3 +36,8 @@ graph:
 docs:
 	echo ">>> View at 'http://localhost:6060/pkg/git.maximhutz.com/max/lambda/'"
 	go run golang.org/x/tools/cmd/godoc@latest -http=:6060
+
+clean:
+	rm -f ${BINARY_NAME}
+	rm -f program.out
+	rm -rf profile/