chore: add ESLint config with TypeScript-recommended rules (minimal, any allowed, _-prefix unused vars as warn)

Author: Bubba

.eslintrc.cjs

@@ -0,0 +1,31 @@
+// @ts-check
+'use strict';
+
+/** @type {import('eslint').Linter.Config} */
+module.exports = {
+  root: true,
+  parser: '@typescript-eslint/parser',
+  parserOptions: {
+    ecmaVersion: 2020,
+    sourceType: 'module',
+  },
+  plugins: ['@typescript-eslint'],
+  extends: [
+    'eslint:recommended',
+    'plugin:@typescript-eslint/recommended',
+  ],
+  rules: {
+    // Allow explicit `any` — codebase uses it intentionally in many places
+    '@typescript-eslint/no-explicit-any': 'off',
+    // Allow unused vars prefixed with _ (common pattern in this codebase)
+    '@typescript-eslint/no-unused-vars': ['warn', { argsIgnorePattern: '^_', varsIgnorePattern: '^_' }],
+    // Allow require() in .cjs files
+    '@typescript-eslint/no-var-requires': 'off',
+  },
+  ignorePatterns: [
+    'dist/',
+    'node_modules/',
+    'coverage/',
+    '*.d.ts',
+  ],
+};