Import project configuration: backend/eslint.config.mjs

Import the existing local project snapshot. This commit organizes existing files; it does not represent newly developed functionality.

backend/eslint.config.mjs

@@ -0,0 +1,36 @@
+import js from "@eslint/js";
+import tseslint from "typescript-eslint";
+
+export default [
+  {
+    ignores: ["dist/**", "node_modules/**", "coverage/**"],
+  },
+  js.configs.recommended,
+  ...tseslint.configs.recommended,
+  {
+    files: ["**/*.ts"],
+    languageOptions: {
+      parserOptions: {
+        project: false,
+      },
+    },
+    rules: {
+      "@typescript-eslint/no-explicit-any": "off",
+      "@typescript-eslint/no-unused-vars": [
+        "warn",
+        { argsIgnorePattern: "^_", varsIgnorePattern: "^_", caughtErrorsIgnorePattern: "^_" },
+      ],
+      "no-empty": "off",
+    },
+  },
+  {
+    files: ["**/*.js", "**/*.mjs"],
+    languageOptions: {
+      globals: {
+        Buffer: "readonly",
+        console: "readonly",
+        process: "readonly",
+      },
+    },
+  },
+];