🤖 feat: implement trunk-based CI/CD with local testing

- Designed trunk-based development workflow with branch protection
- Added workflow validation job to prevent main branch breaks
- Integrated act (GitHub Actions runner) for local Gitea workflow testing
- Created unified CI/CD script interface (scripts/cicd.sh)
- Added YAML lint configuration with practical limits (400 chars)
- Organized all CI/CD scripts under scripts/cicd/ directory
- Confirmed Gitea/GitHub Actions compatibility via local testing
- Updated ADR 0017 with implementation details and test results
- Enhanced documentation with local development workflow

See ADR-0017 for complete trunk-based development workflow documentation.
See ADR-0016 for CI/CD pipeline design.

docker-compose.cicd-test.yml

@@ -0,0 +1,29 @@
+version: '3.8'
+
+services:
+  act-runner:
+    image: gitea/act_runner:latest
+    volumes:
+      - .:/workspace
+      - ./config/runner:/data/.runner
+    working_dir: /workspace
+    environment:
+      - GITEA_INSTANCE_URL=${GITEA_INSTANCE_URL:-https://gitea.arcodange.lab/}
+      - GITEA_RUNNER_REGISTRATION_TOKEN=${GITEA_RUNNER_REGISTRATION_TOKEN}
+      - GITEA_RUNNER_NAME=${GITEA_RUNNER_NAME:-local-test-runner}
+      - GITEA_RUNNER_LABELS=${GITEA_RUNNER_LABELS:-ubuntu-latest:docker://node:16-bullseye,ubuntu-22.04:docker://gitea/act_runner:latest}
+    command: act -W .gitea/workflows/ci-cd.yaml --rm
+
+  yamllint:
+    image: pipelinecomponents/yamllint:latest
+    volumes:
+      - .:/workspace
+    working_dir: /workspace
+    command: yamllint .gitea/workflows/
+
+  yq-validator:
+    image: mikefarah/yq:latest
+    volumes:
+      - .:/workspace
+    working_dir: /workspace
+    command: yq eval '.' .gitea/workflows/ci-cd.yaml