chore: repair pre-existing lint failures blocking the lint gate

- turbo/generators/config.ts used require() inside the reader generator
  action (no-require-imports); use the top-level node:fs imports
- auth authentication.service.ts used a literal self-assertion
  ("users" as "users"); prefer-as-const
- apps/cms lacked web-next's next-env.d.ts triple-slash-reference
  override, and the committed next-env.d.ts now references
  .next/types/routes.d.ts

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

apps/cms/eslint.config.js

@@ -1,3 +1,11 @@
 import baseConfig from "@repo/core-eslint/base";
 
-export default baseConfig;
+export default [
+  ...baseConfig,
+  {
+    files: ["next-env.d.ts"],
+    rules: {
+      "@typescript-eslint/triple-slash-reference": "off",
+    },
+  },
+];