feat: implement quality-gate and publish-artifact pipelines

- Rename build-feature.yml → quality-gate.yml (merge-portti)
- Create build_publish-artifact.yml: check → qg → build → push → tag
- Add minimal Dockerfile for dogfood container build
- Simplify quality-gate.yml cucumber job (remove prepare step, TOOL_OK)
- Standardize test scripts in package.json for Docker-based local + CI runs
- Update ci.yml: main branch uses build_publish-artifact.yml
- Update docs/workflows.md: feature section rewritten with provider model
- Add .gitignore entries for coverage/ and reports/

.gitignore

@@ -4,3 +4,6 @@ AGENTS.md
 .ai
 node_modules/
 tmp/
+coverage/
+.DS_Store
+reports/