ci: deploy the verified local image

Build and test the Next.js application once with persistent BuildKit caches, smoke-test the immutable runtime image, and activate that same image through the shared production Docker daemon with serialized rollback-safe deployment.

compose.yaml

@@ -1,17 +1,20 @@
 services:
   portfolio-app:
-    image: amiirkhl-portfolio:latest
-    build:
-      context: .
-      dockerfile: Dockerfile
+    image: ${PORTFOLIO_IMAGE:-amiirkhl-portfolio:latest}
     container_name: portfolio-app
     restart: unless-stopped
     healthcheck:
-      test: ["CMD", "wget", "--no-verbose", "--tries=1", "--spider", "http://127.0.0.1:3000/"]
-      interval: 30s
-      timeout: 3s
-      start_period: 10s
-      retries: 3
+      test:
+        [
+          "CMD",
+          "node",
+          "-e",
+          "fetch('http://127.0.0.1:3000/').then(r=>{if(!r.ok)process.exit(1)}).catch(()=>process.exit(1))",
+        ]
+      interval: 2s
+      timeout: 2s
+      start_period: 3s
+      retries: 30
     volumes:
       - next-image-cache:/app/.next/cache
     networks: