fix(ui): restore webpack 5 production build and dependency resolution

- replace webpack 4-only production plugins with webpack 5 equivalents
- restore extracted CSS, asset-manifest generation, and service-worker output
- remove the legacy peer dependency install workaround from the UI build script
- align ui package dependencies and regenerate the lockfile to install cleanly
- replace the outdated ts-jest preprocessor shim with a local TypeScript Jest transform
- revert dist/npm inquirer and find-process to CommonJS-safe versions
- tighten configToYAML typing and align CustomNavLink active state with NavLink semantics
- fix TerminalCache typing so the UI build passes lint and type checks