ci: Add automated Docker build validation workflow

.github/workflows/docker-validation.yml

@@ -0,0 +1,40 @@
+name: Docker Build Validation
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  build-docker-images:
+    name: Build Docker Images
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build Backend Image
+        uses: docker/build-push-action@v5
+        with:
+          context: ./backend
+          file: ./backend/Dockerfile
+          push: false
+          tags: secuscan-backend:latest
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+
+      - name: Build Frontend Image
+        uses: docker/build-push-action@v5
+        with:
+          context: ./frontend
+          file: ./frontend/Dockerfile
+          push: false
+          tags: secuscan-frontend:latest
+          cache-from: type=gha
+          cache-to: type=gha,mode=max