migrate to new eslint config file

eslint.config.mjs

@@ -0,0 +1,68 @@
+import typescriptEslint from "@typescript-eslint/eslint-plugin";
+import globals from "globals";
+import tsParser from "@typescript-eslint/parser";
+import parser from "svelte-eslint-parser";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import js from "@eslint/js";
+import { FlatCompat } from "@eslint/eslintrc";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const compat = new FlatCompat({
+    baseDirectory: __dirname,
+    recommendedConfig: js.configs.recommended,
+    allConfig: js.configs.all
+});
+
+export default [{
+    ignores: [
+        "**/.DS_Store",
+        "**/node_modules",
+        "build",
+        ".svelte-kit",
+        "package",
+        "**/.env",
+        "**/.env.*",
+        "!**/.env.example",
+        "**/pnpm-lock.yaml",
+        "**/package-lock.json",
+        "**/yarn.lock",
+    ],
+}, ...compat.extends(
+    "eslint:recommended",
+    "plugin:@typescript-eslint/recommended",
+    "plugin:svelte/recommended",
+    "prettier",
+), {
+    plugins: {
+        "@typescript-eslint": typescriptEslint,
+    },
+
+    languageOptions: {
+        globals: {
+            ...globals.browser,
+            ...globals.node,
+        },
+
+        parser: tsParser,
+        ecmaVersion: 2020,
+        sourceType: "module",
+
+        parserOptions: {
+            extraFileExtensions: [".svelte"],
+        },
+    },
+}, {
+    files: ["**/*.svelte"],
+
+    languageOptions: {
+        parser: parser,
+        ecmaVersion: 5,
+        sourceType: "script",
+
+        parserOptions: {
+            parser: "@typescript-eslint/parser",
+        },
+    },
+}];

package.json

@@ -14,6 +14,8 @@
 		"format": "prettier --write ."
 	},
 	"devDependencies": {
+		"@eslint/eslintrc": "^3.1.0",
+		"@eslint/js": "^9.11.1",
 		"@sveltejs/adapter-auto": "^3.2.5",
 		"@sveltejs/adapter-static": "^3.0.5",
 		"@sveltejs/kit": "^2.6.1",
@@ -24,6 +26,7 @@
 		"eslint": "^9.11.1",
 		"eslint-config-prettier": "^9.1.0",
 		"eslint-plugin-svelte": "^2.44.1",
+		"globals": "^15.9.0",
 		"prettier": "^3.3.3",
 		"prettier-plugin-svelte": "^3.2.7",
 		"svelte": "^4.2.19",