ci: adds shared reusable setup polytest and mock server actions

.github/actions/setup-polytest/action.yml

@@ -0,0 +1,17 @@
+name: Setup Polytest
+description: Install Rust and polytest CLI
+
+inputs:
+  version:
+    description: Polytest version (empty for latest)
+    required: false
+    default: ""
+
+runs:
+  using: composite
+  steps:
+    - uses: dtolnay/rust-toolchain@stable
+
+    - name: Install polytest
+      shell: bash
+      run: cargo install polytest --locked ${{ inputs.version && format('--version {0}', inputs.version) || '' }}

.github/workflows/publish-docker.yml

@@ -0,0 +1,40 @@
+name: Publish Mock Server
+
+on:
+  push:
+    branches: [main]
+    paths: ['resources/mock-server/**']
+  workflow_dispatch: # Manual trigger for testing from any branch
+
+env:
+  IMAGE: ghcr.io/aorumbayev/polytest-mock-server
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: docker/setup-buildx-action@v3
+
+      - uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          context: ./resources/mock-server
+          push: true
+          tags: |
+            ${{ env.IMAGE }}:latest
+            ${{ env.IMAGE }}:${{ github.sha }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+          platforms: linux/amd64,linux/arm64