Replace the previous frontend workflow with an expanded Build, Test & Push workflow. Adds a quality-check job (runs on push and PRs to main) that sets up Node.js, installs deps, runs lint/type checks, unit tests (ChromeHeadless), production build and runs LHCI. The docker job now depends on the quality-check job and only runs on pushes to main. Added lighthouserc.json and ignored .lighthouseci, relaxed two ESLint rules (@typescript-eslint/no-inferrable-types and no-explicit-any), and updated package.json (and lock) to include LHCI tooling.
