perf(ci): parallelize docker builds + add npm cache mount

Split single build-and-deploy job into 4 jobs: build-backend,
build-worker, build-frontend run in parallel (all 3 independent),
deploy job has needs:[...] on all three. Removes ~2 min of sequential
build time on warm cache runs.

Also: scope GHA cache keys per image (backend-lean / worker-chromium /
frontend) so builds don't invalidate each other's layer cache. Replace
sleep 8 health-check with a 30-iteration polling loop (fails fast on
bad deploy, doesn't over-wait on fast ones). Add --mount=type=cache to
frontend npm ci for node_modules cache across builds.

.github/workflows/deploy.yml

@@ -25,7 +25,7 @@ env:
   IMAGE_FRONTEND: ghcr.io/lekss361/gendesign-frontend
 
 jobs:
-  build-and-deploy:
+  build-backend:
     runs-on: ubuntu-latest
     permissions:
       contents: read
@@ -34,10 +34,6 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Set image tag
-        id: meta
-        run: echo "tag=${GITHUB_SHA::7}" >> "$GITHUB_OUTPUT"
-
       - name: Login to GHCR
         uses: docker/login-action@v3
         with:
@@ -54,11 +50,30 @@ jobs:
           context: ./backend
           target: runner
           push: true
-          cache-from: type=gha,scope=backend
+          cache-from: type=gha,scope=backend-lean
-          cache-to: type=gha,mode=max,scope=backend
+          cache-to: type=gha,mode=max,scope=backend-lean
           tags: |
             ${{ env.IMAGE_BACKEND }}:latest
-            ${{ env.IMAGE_BACKEND }}:${{ steps.meta.outputs.tag }}
+            ${{ env.IMAGE_BACKEND }}:${{ github.sha }}
+
+  build-worker:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    if: github.event_name == 'workflow_dispatch' || github.ref == 'refs/heads/main'
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Login to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
 
       - name: Build & push worker (с Chromium для Playwright)
         uses: docker/build-push-action@v6
@@ -66,11 +81,30 @@ jobs:
           context: ./backend
           target: runner-with-chromium
           push: true
-          cache-from: type=gha,scope=worker
+          cache-from: type=gha,scope=worker-chromium
-          cache-to: type=gha,mode=max,scope=worker
+          cache-to: type=gha,mode=max,scope=worker-chromium
           tags: |
             ${{ env.IMAGE_WORKER }}:latest
-            ${{ env.IMAGE_WORKER }}:${{ steps.meta.outputs.tag }}
+            ${{ env.IMAGE_WORKER }}:${{ github.sha }}
+
+  build-frontend:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    if: github.event_name == 'workflow_dispatch' || github.ref == 'refs/heads/main'
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Login to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
 
       - name: Build & push frontend
         uses: docker/build-push-action@v6
@@ -81,12 +115,18 @@ jobs:
           cache-to: type=gha,mode=max,scope=frontend
           tags: |
             ${{ env.IMAGE_FRONTEND }}:latest
-            ${{ env.IMAGE_FRONTEND }}:${{ steps.meta.outputs.tag }}
+            ${{ env.IMAGE_FRONTEND }}:${{ github.sha }}
 
+  deploy:
+    runs-on: ubuntu-latest
+    needs: [build-backend, build-worker, build-frontend]
+    permissions:
+      contents: read
+    steps:
       - name: Deploy to VM via SSH
         uses: appleboy/ssh-action@v1.0.3
         env:
-          IMAGE_TAG: ${{ steps.meta.outputs.tag }}
+          IMAGE_TAG: ${{ github.sha }}
         with:
           host: ${{ secrets.DEPLOY_HOST }}
           username: ${{ secrets.DEPLOY_USER }}
@@ -137,5 +177,8 @@ jobs:
             docker image prune -af --filter "until=72h" || true
             docker builder prune -af || true
 
-            sleep 8
+            # Wait for backend to be healthy (up to 30 s).
-            curl -fsS http://localhost:8000/health | head -c 200 || true
+            for i in $(seq 1 30); do
+              curl -fsS http://localhost:8000/health && break
+              sleep 1
+            done

frontend/Dockerfile

@@ -5,7 +5,8 @@ FROM node:20-alpine AS deps
 WORKDIR /app
 COPY package.json package-lock.json ./
 # --legacy-peer-deps: Tailwind 4 alpha + React 19 peer-dep mismatches.
-RUN npm ci --legacy-peer-deps --no-audit --no-fund
+RUN --mount=type=cache,target=/root/.npm \
+    npm ci --legacy-peer-deps --no-audit --no-fund
 
 
 # ---- builder ----