chore: move frontend build to action

.github/workflows/build-and-push-canary-image.yml

@@ -57,6 +57,21 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ github.token }}
 
+      # Frontend build.
+      - uses: pnpm/action-setup@v4.1.0
+        with:
+          version: 10
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "22"
+          cache: pnpm
+          cache-dependency-path: "web/pnpm-lock.yaml"
+      - run: pnpm install
+        working-directory: web
+      - name: Run frontend build
+        run: pnpm release
+        working-directory: web
+
       - name: Build and Push
         id: docker_build
         uses: docker/build-push-action@v6

scripts/Dockerfile

-# Build frontend dist.
-FROM node:20-alpine AS frontend
-WORKDIR /frontend-build
-
-COPY . .
-
-WORKDIR /frontend-build/web
-
-RUN npm install -g pnpm
-RUN pnpm i --frozen-lockfile
-RUN pnpm build
-
-# Build backend exec file.
 FROM golang:1.24-alpine AS backend
 WORKDIR /backend-build
 
 COPY . .
-COPY --from=frontend /frontend-build/web/dist /backend-build/server/router/frontend/dist
+# Please build frontend first, so that the static files are available.
+# Refer to `pnpm release` in package.json for the build command.
 
 RUN go build -o memos ./bin/memos/main.go