DC-074: Multi-stage Dockerfile — builder stage installs all deps, production
stage copies only node_modules + source. Reduces image size by excluding
devDependencies from the final image.
DC-091: .github/dependabot.yml — weekly npm + GitHub Actions dependency
updates. Groups dev vs production deps separately, limits to 5 open PRs.
All 1540 tests pass.
Runs on push/PR to main: npm ci → ESLint (no warnings) → Jest with coverage → upload artifact.
Uses permissions: contents: read for supply-chain hardening.
Node 20 matches package.json engine requirement.