Add GitHub Actions workflow for building and pushing Docker images; remove old deploy workflow

Author: dmitryesin

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

@@ -0,0 +1,44 @@
+name: Build and Push Docker Images
+
+on:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Verify DockerHub credentials
+        run: |
+          if [ -z "${{ secrets.DOCKERHUB_USERNAME }}" ] || [ -z "${{ secrets.DOCKERHUB_PASSWORD }}" ]; then
+            echo "Missing DockerHub credentials"
+            exit 1
+          fi
+
+      - name: Log in to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          registry: docker.io
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_PASSWORD }}
+
+      - name: Build and push diffy-bot-client
+        uses: docker/build-push-action@v4
+        with:
+          context: .
+          file: solver-bot/Dockerfile
+          push: true
+          tags: ${{ secrets.DOCKERHUB_USERNAME }}/diffy-bot-client:latest
+
+      - name: Build and push diffy-bot-server
+        uses: docker/build-push-action@v4
+        with:
+          context: .
+          file: solver-common/Dockerfile
+          push: true
+          tags: ${{ secrets.DOCKERHUB_USERNAME }}/diffy-bot-server:latest