refactor: remove swagger, fix docs, upgrade eslint plugin in NestJS example
Remove @nestjs/swagger from example and docs — unnecessary for demonstrating
the plugin. Upgrade @darraghor/eslint-plugin-nestjs-typed to v7 with flat
config support. Extract shared configureApp() factory. Update nest.md to
remove stale swagger references and document cookie parameter limitation.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>