build(deps): migrate to ESLint flat config, eslint 10 & typescript-eslint 8

eslint.config.mjs

@@ -0,0 +1,52 @@
+import js from '@eslint/js';
+import tseslint from 'typescript-eslint';
+import importX from 'eslint-plugin-import-x';
+import globals from 'globals';
+
+// Flat-config port of the previous .eslintrc. Kept intentionally
+// non-type-checked (no parserOptions.project) to preserve the existing rule
+// profile; enabling type-aware linting is a separate, larger change.
+export default tseslint.config(
+  {
+    ignores: ['node_modules/**', '.vite/**', 'out/**', 'build/**', 'coverage/**'],
+  },
+  js.configs.recommended,
+  ...tseslint.configs.recommended,
+  importX.flatConfigs.recommended,
+  importX.flatConfigs.electron,
+  importX.flatConfigs.typescript,
+  {
+    files: ['**/*.{ts,tsx,mts,cts}'],
+    languageOptions: {
+      parser: tseslint.parser,
+      ecmaVersion: 'latest',
+      sourceType: 'module',
+      globals: { ...globals.browser, ...globals.node },
+    },
+    settings: {
+      'import-x/resolver': {
+        typescript: { project: './tsconfig.json' },
+        node: true,
+      },
+    },
+  },
+  {
+    // Plain JS tooling (build scripts, this config) runs on Node.
+    files: ['**/*.{js,mjs,cjs}'],
+    languageOptions: { globals: { ...globals.node } },
+  },
+  {
+    // Build/config files import tooling that the resolver can't always see.
+    files: ['**/*.config.{ts,mts,cts}'],
+    rules: { 'import-x/no-unresolved': 'off' },
+  },
+  {
+    // The typescript-eslint / import-x meta packages mix default and named
+    // exports, which trips these stylistic import checks on this config only.
+    files: ['eslint.config.mjs'],
+    rules: {
+      'import-x/no-named-as-default': 'off',
+      'import-x/no-named-as-default-member': 'off',
+    },
+  },
+);