build: use WEB_GO for web targets and preserve backend dist directory (#1671)

Separate web Go commands from the default Go toolchain so web builds,
tests, and vet can enable CGO on Darwin without affecting the rest of
the project. Also ensure frontend backend builds recreate backend/dist
with a .gitkeep file so the embedded output directory remains tracked.

web/Makefile

@@ -1,17 +1,18 @@
 .PHONY: dev dev-frontend dev-backend build test lint clean
 
+# Go variables
+GO?=CGO_ENABLED=0 go
+WEB_GO?=$(GO)
+GOFLAGS?=-v -tags stdjson
+
 # Version
 VERSION?=$(shell git describe --tags --always --dirty 2>/dev/null || echo "dev")
 GIT_COMMIT=$(shell git rev-parse --short=8 HEAD 2>/dev/null || echo "dev")
 BUILD_TIME=$(shell date +%FT%T%z)
-GO_VERSION=$(shell $(GO) version | awk '{print $$3}')
+GO_VERSION=$(shell $(WEB_GO) version | awk '{print $$3}')
 CONFIG_PKG=github.com/sipeed/picoclaw/pkg/config
 LDFLAGS=-X $(CONFIG_PKG).Version=$(VERSION) -X $(CONFIG_PKG).GitCommit=$(GIT_COMMIT) -X $(CONFIG_PKG).BuildTime=$(BUILD_TIME) -X $(CONFIG_PKG).GoVersion=$(GO_VERSION) -s -w
 
-# Go variables
-GO?=CGO_ENABLED=0 go
-GOFLAGS?=-v -tags stdjson
-
 
 # OS detection
 UNAME_S:=$(shell uname -s)
@@ -37,7 +38,7 @@ ifeq ($(UNAME_S),Linux)
 	endif
 else ifeq ($(UNAME_S),Darwin)
 	PLATFORM=darwin
-	GO=CGO_ENABLED=1 go
+	WEB_GO=CGO_ENABLED=1 go
 	ifeq ($(UNAME_M),x86_64)
 		ARCH=amd64
 	else ifeq ($(UNAME_M),arm64)
@@ -69,21 +70,21 @@ dev-frontend:
 
 # Start backend dev server
 dev-backend:
-	cd backend && ${GO} run  -ldflags "$(LDFLAGS)" .
+	cd backend && ${WEB_GO} run -ldflags "$(LDFLAGS)" .
 
 # Build frontend and embed into Go binary
 build:
 	cd frontend && pnpm build:backend
-	cd backend && ${GO} build $(GOFLAGS) -ldflags "$(LDFLAGS)" -o picoclaw-web .
+	cd backend && ${WEB_GO} build $(GOFLAGS) -ldflags "$(LDFLAGS)" -o picoclaw-web .
 
 # Run all tests
 test:
-	cd backend && ${GO} test ./...
+	cd backend && ${WEB_GO} test ./...
 	cd frontend && pnpm lint
 
 # Lint and format
 lint:
-	cd backend && ${GO} vet ./...
+	cd backend && ${WEB_GO} vet ./...
 	cd frontend && pnpm check
 
 # Clean build artifacts

web/frontend/package.json

@@ -6,7 +6,7 @@
   "scripts": {
     "dev": "vite",
     "build": "tsc -b && vite build",
-    "build:backend": "tsc -b && vite build --outDir ../backend/dist --emptyOutDir",
+    "build:backend": "tsc -b && vite build --outDir ../backend/dist --emptyOutDir && node ./scripts/ensure-backend-gitkeep.cjs",
     "lint": "eslint .",
     "preview": "vite preview",
     "format": "prettier --check .",

web/frontend/scripts/ensure-backend-gitkeep.cjs

@@ -0,0 +1,9 @@
+const fs = require("node:fs")
+const path = require("node:path")
+
+const gitkeepPath = path.resolve(__dirname, "../../backend/dist/.gitkeep")
+const gitkeepContents =
+  "# Keep the embedded web backend dist directory in version control.\n"
+
+fs.mkdirSync(path.dirname(gitkeepPath), { recursive: true })
+fs.writeFileSync(gitkeepPath, gitkeepContents)