PR-227028: update dependencies, migrate to TypeScript 6 and ESLint flat config

- Bump all dependencies to latest (React 19.2.7, Storybook 10.4.3, Webpack
  5.107.2 + webpack-cli 7, Jest 30.4.2, Cypress 15.17.0, Babel 7.29.7,
  sass-loader 17, css-minimizer-webpack-plugin 8, eslint-webpack-plugin 6).
- Migrate TypeScript 5.9 -> 6.0.3: set tsconfig rootDir, add
  ignoreDeprecations "6.0", scope include to src/components + src/@types, and
  declare *.scss/*.sass/*.css modules for stricter side-effect imports.
- Switch @babel/preset-react to the automatic JSX runtime and drop redundant
  React imports in stories and tests.
- Migrate ESLint from the deprecated .eslintrc.js to flat config
  (eslint.config.mjs) using typescript-eslint, @eslint/js, globals and the
  React/Storybook plugins. Keep ESLint at v9 because eslint-plugin-react does
  not support v10 yet. This fixes the previously broken lint (missing
  @typescript-eslint parser/plugin) and normalizes formatting.
- Fix a latent bug in .storybook/main.js (comma instead of semicolon joining
  two assignments via the comma operator).
- npm audit fix: 0 vulnerabilities.
- Bump package version to 1.4.0.

eslint.config.mjs

@@ -0,0 +1,50 @@
+import js from '@eslint/js';
+import tseslint from 'typescript-eslint';
+import react from 'eslint-plugin-react';
+import storybook from 'eslint-plugin-storybook';
+import globals from 'globals';
+
+export default tseslint.config(
+	{
+		ignores: ['node_modules/**', 'dist/**', 'build/**', 'storybook-static/**'],
+	},
+	js.configs.recommended,
+	...tseslint.configs.recommended,
+	react.configs.flat.recommended,
+	react.configs.flat['jsx-runtime'],
+	...storybook.configs['flat/recommended'],
+	{
+		settings: {
+			react: { version: 'detect' },
+		},
+	},
+	{
+		files: ['**/*.{js,jsx,ts,tsx}'],
+		languageOptions: {
+			ecmaVersion: 'latest',
+			sourceType: 'module',
+			parserOptions: {
+				ecmaFeatures: { jsx: true },
+			},
+			globals: {
+				...globals.browser,
+				...globals.node,
+			},
+		},
+		rules: {
+			indent: ['error', 'tab'],
+			'linebreak-style': ['error', 'unix'],
+			quotes: ['error', 'single'],
+			semi: ['error', 'always'],
+			'eol-last': ['error', 'always'],
+			'react/prop-types': 'off',
+			'@typescript-eslint/no-require-imports': 'off',
+		},
+	},
+	{
+		files: ['**/*.js'],
+		languageOptions: {
+			sourceType: 'commonjs',
+		},
+	},
+);