Upgrade dev tooling: webpack 5, eslint 8, prettier 3, husky 9

Major upgrades:
- webpack 4 → 5 (styleguide, vanilla-drylus, extract-emotion)
- webpack-cli 3 → 5, webpack-dev-server 3 → 5
- html-webpack-plugin 3 → 5, copy-webpack-plugin 5 → 12
- css-loader 2 → 7, style-loader 0.23 → 4, ts-loader 8 → 9
- babel-loader 8 → 9, tsconfig-paths-webpack-plugin 3 → 4
- eslint 6 → 8, babel-eslint → @babel/eslint-parser
- eslint-plugin-react 7.12 → 7.37, eslint-plugin-jest 23 → 27
- eslint-formatter-pretty 2 → 4
- prettier 1 → 3, husky 1 → 9, lint-staged 8 → 15
- rimraf 2 → 6

Removals:
- react-hot-loader + @hot-loader/react-dom (unused with webpack 5)
- memory-fs (replaced by memfs for webpack 5)
- file-loader (replaced by webpack 5 asset modules)
- friendly-errors-webpack-plugin, better-webpack-progress
- prettier-plugin-import-sort, import-sort-style-module
- Deprecated babel proposal plugins (using transform variants)

This removes all NODE_OPTIONS=--openssl-legacy-provider workarounds.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: LaurentClaes

.eslintrc.js

@@ -1,5 +1,5 @@
 module.exports = {
-  parser: 'babel-eslint',
+  parser: '@babel/eslint-parser',
   env: {
     browser: true,
     es6: true,
@@ -8,15 +8,13 @@ module.exports = {
   },
   parserOptions: {
     sourceType: 'module',
-    ecmaFeatures: {
-      experimentalObjectRestSpread: true,
-    },
+    requireConfigFile: false,
   },
   extends: [ 'eslint:recommended', 'plugin:react/recommended' ],
   plugins: [ 'react' ],
   settings: {
     react: {
-      version: 'latest',
+      version: 'detect',
     },
   },
   rules: {
@@ -36,7 +34,7 @@ module.exports = {
     'no-lone-blocks': [ 'warn' ],
     'no-loop-func': [ 'warn' ],
     'no-multi-str': [ 'warn' ],
-    'no-native-reassign': [ 'warn' ],
+    'no-global-assign': [ 'warn' ],
     'no-new-wrappers': [ 'warn' ],
     'no-script-url': [ 'warn' ],
     'no-self-compare': [ 'warn' ],

.eslintrc.ts.js

@@ -29,7 +29,7 @@ module.exports = {
     'no-lone-blocks': ['warn'],
     'no-loop-func': ['warn'],
     'no-multi-str': ['warn'],
-    'no-native-reassign': ['warn'],
+    'no-global-assign': ['warn'],
     'no-new-wrappers': ['warn'],
     'no-script-url': ['warn'],
     'no-self-compare': ['warn'],

.husky/pre-commit

@@ -0,0 +1 @@
+npx lint-staged

.prettierrc

@@ -6,7 +6,6 @@
   "singleQuote": true,
   "trailingComma": "all",
   "bracketSpacing": true,
-  "jsxBracketSameLine": true,
-  "fluid": false,
+  "bracketSameLine": true,
   "arrowParens": "always"
 }

babel.config.js

@@ -19,7 +19,6 @@ module.exports = function(api) {
   ];
 
   const plugins = [
-    ...(isTest ? [] : ['react-hot-loader/babel']),
     ...(isTest ? [] : [['babel-plugin-emotion', {
       sourceMap: false,
       autoLabel: true,