Modernize dependencies

[pokutuna]

Bring the dependency tree up to date in stages, verifying tests and build at each step.

Already done in a recent batch: TypeScript 6, gts 7, Jest 30 / ts-jest 29, ESLint 9 (flat config), @testing-library 6/16.

Remaining candidates:

• @types/chrome (0.0.191 → 0.1.40, ~3 years stale)
• husky 8 → 9, lint-staged 12 → 16
• webpack-cli 4 → 7, css-loader 6 → 7, style-loader 3 → 4
• @fortawesome/* 6 → 7, chroma-js 2 → 3
• react 18 → 19, styled-components 5 → 6, react-router-dom 6 → 7
• Drop unused jsx-runtime package (verify first)
• Reconsider the @types/react resolution pin once on React 19