chore(lint): adopt eslint-config-codex 2.x

1.x checks indentation with ESLint's base `indent` rule, which cannot
see TypeScript syntax. Indentation inside TS constructs was therefore
never checked at all. 2.x uses @stylistic/indent, which reads it.

2.x ships flat config only, so .eslintrc.js becomes eslint.config.mjs,
and eslint and typescript move up to satisfy it. tsconfig drops
baseUrl on the way, since TypeScript 7 removes it.

eslint-plugin-n rules are disabled where they resolve imports as Node
does and report existing .ts files as missing.

Applying the fixes is left for a separate commit; src/ is untouched.

Author: Reversean

.eslintrc.js

@@ -0,0 +1,50 @@
+import CodeX from 'eslint-config-codex';
+
+export default [
+  ...CodeX,
+
+  {
+    rules: {
+      /**
+       * Downgraded in .eslintrc.js, kept that way here.
+       */
+      'no-shadow': 'warn',
+      'no-unused-expressions': 'warn',
+
+      /**
+       * Resolves imports as Node does and never looks for .ts.
+       */
+      'n/no-missing-import': 'off',
+
+      /**
+       * Demand require('process') and require('buffer') over the globals.
+       */
+      'n/prefer-global/process': 'off',
+      'n/prefer-global/buffer': 'off',
+    },
+  },
+
+  {
+    /**
+     * CodeX registers @typescript-eslint and jsdoc for *.ts only, and resolves
+     * tsconfigRootDir inside its own package.
+     */
+    files: ['**/*.ts'],
+    languageOptions: {
+      parserOptions: {
+        project: './tsconfig.json',
+        tsconfigRootDir: import.meta.dirname,
+        sourceType: 'module',
+      },
+    },
+    rules: {
+      /**
+       * Downgraded in .eslintrc.js, kept that way here. `jsdoc/require-jsdoc`
+       * replaces the removed core `require-jsdoc`.
+       */
+      '@typescript-eslint/no-unused-vars': 'warn',
+      '@typescript-eslint/explicit-function-return-type': 'warn',
+      'jsdoc/require-jsdoc': 'warn',
+    },
+  },
+];

eslint.config.mjs

@@ -6,8 +6,8 @@
   "scripts": {
     "dev": "ts-node-dev --no-notify index.ts",
     "start": "node index.ts",
-    "lint": "eslint -c ./.eslintrc.js src/ --ext .ts,.js --fix",
-    "lint-test": "eslint -c ./.eslintrc.js src/ --ext .ts,.js",
+    "lint": "eslint ./src --fix",
+    "lint-test": "eslint ./src",
     "dev:up": "docker-compose -f docker-compose.dev.yml up -d",
     "dev:down": "docker-compose -f docker-compose.dev.yml down",
     "build": "tsc",
@@ -24,16 +24,16 @@
     "@swc/core": "^1.3.0",
     "@types/jest": "^29.5.0",
     "@types/xml2js": "^0.4.14",
-    "eslint": "^6.7.2",
-    "eslint-config-codex": "1.2.4",
+    "eslint": "^9.39.5",
+    "eslint-config-codex": "^2.0.3",
     "eslint-plugin-import": "^2.19.1",
     "jest": "^30.2.0",
     "mongodb-memory-server": "^6.6.1",
     "nodemon": "^2.0.2",
     "redis-mock": "^0.56.3",
     "ts-jest": "^29.4.0",
     "ts-node": "^10.9.1",
-    "typescript": "^4.7.4",
+    "typescript": "^6.0.3",
     "xml2js": "^0.6.2"
   },
   "dependencies": {

package.json

@@ -41,9 +41,8 @@
 
     /* Module Resolution Options */
     // "moduleResolution": "node",            /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
-    "baseUrl": "./",                       /* Base directory to resolve non-absolute module names. */
-    "paths": {                           /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
-      "zod/v4": ["src/types/zod-v4.d.ts"]
+    "paths": {                                /* A series of entries which re-map imports to lookup locations relative to this file. */
+      "zod/v4": ["./src/types/zod-v4.d.ts"]
     },
     // "rootDirs": [],                        /* List of root folders whose combined content represents the structure of the project at runtime. */
     // "typeRoots": [],                       /* List of folders to include type definitions from. */