Replace CircleCI with GitHub Actions workflow

- Remove CircleCI configuration and helper scripts
- Add GitHub Actions workflow that runs build-and-test-all.sh
- Use Gradle action for dependency caching
- Upload test reports as artifacts on completion

Co-authored by Claude Code

Author: cer

.circleci/config.yml

@@ -0,0 +1,42 @@
+name: Build and Test
+
+on:
+  push:
+    paths-ignore:
+      - 'docs/**'
+      - '*.md'
+  pull_request:
+    paths-ignore:
+      - 'docs/**'
+      - '*.md'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+
+    - name: Set up JDK 17
+      uses: actions/setup-java@v4
+      with:
+        java-version: '17'
+        distribution: 'temurin'
+
+    - name: Setup Gradle
+      uses: gradle/actions/setup-gradle@v4
+      with:
+        cache-read-only: false
+
+    - name: Build and test all services
+      run: ./build-and-test-all.sh
+
+    - name: Save test results
+      if: ${{ always() }}
+      uses: actions/upload-artifact@v4
+      with:
+        name: test-reports
+        path: |
+          **/build/reports
+          **/build/test-results