Automatically detect missing updates to OpenAPI specs and client (#15)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

.github/workflows/generate-api-client.yml

@@ -0,0 +1,59 @@
+name: OpenAPI
+
+on:
+  pull_request:
+    paths:
+      - 'server/application-server/**'
+      - '.github/workflows/generate-api-client.yml'
+  push:
+    paths:
+      - 'server/application-server/openapi.yaml'
+      - 'webapp/src/app/core/modules/openapi/**'
+  workflow_dispatch:
+
+concurrency:
+  group: generate-api-client
+  cancel-in-progress: true
+
+jobs:
+  generate-api-client:
+    name: Verify API Specs and Client
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.pull_request.head.ref }}
+          fetch-depth: 0
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+
+      - name: Set up JDK 21
+        uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: '21'
+
+      - name: Install dependencies
+        run: npm install
+
+      - name: Generate API client
+        run: npm run generate:api
+
+      - name: Check for changes in the API
+        id: check_changes
+        run: |
+          echo "Checking for changes in the API client directory..."
+          git add .
+          if git diff --cached --quiet; then
+            echo "No changes detected in the API client directory."
+            echo "NO_CHANGES_DETECTED=true" >> $GITHUB_ENV
+          else
+            echo "Changes detected in the API client directory."
+            echo "NO_CHANGES_DETECTED=false" >> $GITHUB_ENV
+            exit 1
+          fi