The `@hypothesis/frontend-build` package provides utilities for building frontend assets and running tests in Hypothesis projects, primarily using Gulp tasks. It assumes a standard tech stack including Rollup for JS bundling, Tailwind/Sass for styles, and Vitest for testing, and offers functions for building JS/CSS bundles, watching files, running tests, and generating asset manifests. This package is designed for developers working on Hypothesis frontend projects who follow their established conventions and tooling setup.