Fix Makefile: use -C flag to set module root

Makefile

@@ -27,12 +27,12 @@ help: ## Show this help message
 
 build: ## Build the binary
 	@echo "Building $(BINARY)..."
-	@cd $(ROOTDIR) && $(GOBUILD) -o $(BINARY) $(CMD_PATH)/main.go
+	@$(GOBUILD) -C $(ROOTDIR) -o $(BINARY) cmd/$(BINARY)/main.go
 	@echo "Build complete: $(BINARY)"
 
 build-all: ## Build all binaries
 	@echo "Building all binaries..."
-	@cd $(ROOTDIR) && $(GOBUILD) -o $(BINARY) ./...
+	@$(GOBUILD) -C $(ROOTDIR) -o $(BINARY) ./...
 
 clean: ## Clean build artifacts
 	@echo "Cleaning..."
@@ -42,21 +42,21 @@ clean: ## Clean build artifacts
 
 install: ## Install the binary to $GOPATH/bin
 	@echo "Installing $(BINARY)..."
-	@cd $(ROOTDIR) && $(GOBUILD) -o $$($(GOCMD) env GOPATH)/bin/$(BINARY) $(CMD_PATH)/main.go
+	@$(GOBUILD) -C $(ROOTDIR) -o $$($(GOCMD) env GOPATH)/bin/$(BINARY) cmd/$(BINARY)/main.go
 	@echo "Install complete"
 
 test: ## Run tests
 	@echo "Running tests..."
-	@cd $(ROOTDIR) && $(GOTEST) -v ./...
+	@$(GOTEST) -C $(ROOTDIR) -v ./...
 
 test-coverage: ## Run tests with coverage
 	@echo "Running tests with coverage..."
-	@cd $(ROOTDIR) && $(GOTEST) -v -coverprofile=coverage.out ./...
-	@cd $(ROOTDIR) && $(GOCMD) tool cover -html=coverage.out -o coverage.html
+	@$(GOTEST) -C $(ROOTDIR) -v -coverprofile=coverage.out ./...
+	@$(GOCMD) tool -C $(ROOTDIR) cover -html=coverage.out -o coverage.html
 
 fmt: ## Format Go code
 	@echo "Formatting code..."
-	@cd $(ROOTDIR) && $(GOCMD) fmt ./...
+	@$(GOCMD) fmt -C $(ROOTDIR) ./...
 
 lint: ## Run golangci-lint (if installed)
 	@echo "Running linter..."
@@ -68,8 +68,8 @@ lint: ## Run golangci-lint (if installed)
 
 deps: ## Download dependencies
 	@echo "Downloading dependencies..."
-	@cd $(ROOTDIR) && $(GOMOD) download
-	@cd $(ROOTDIR) && $(GOMOD) tidy
+	@$(GOMOD) -C $(ROOTDIR) download
+	@$(GOMOD) -C $(ROOTDIR) tidy
 
 run: build ## Build and run the binary
 	@echo "Running $(BINARY)..."