Set up native Cursor Cloud dev environment

[jrhoads]

Summary

Sets up the DataCite REST API ("Lupo") to run natively in the Cursor Cloud VM (no Docker), and adds durable instructions for future agents. No application code was modified.

The stack is Ruby 4.0.1 (via rbenv) + Rails 8.1, backed by MySQL 8.0, Memcached, and OpenSearch 2 running locally. Environment-specific files (.env, .bundle/config, Gemfile.dev.lock) are git-ignored and persisted via the VM snapshot.

Changes

• Gemfile.dev — a local-only Gemfile that layers Puma on top of the real Gemfile (the committed Gemfile has no app-server gem because production uses Passenger in Docker). Lets us run rails server natively without touching Gemfile/Gemfile.lock.
• .gitignore — ignore the generated Gemfile.dev.lock.
• AGENTS.md — Cursor Cloud specific instructions: how to start the backing services, environment/.env notes, and lint/test/run commands plus non-obvious gotchas.

Verification

Task	Command	Result
Lint	bundle exec rubocop --parallel	677 files, no offenses
Test	bundle exec rspec spec/models/prefix_spec.rb	4 examples, 0 failures
Run	BUNDLE_GEMFILE=Gemfile.dev bundle exec rails server	Boots in development mode; GET /heartbeat → OK

Hello-world (core functionality): created a draft DOI via the authenticated REST API and read it back:

• POST /dois (staff_admin JWT) → HTTP 201, state: draft, linked to client datacite.testuser
• GET /dois/10.14454/cursor-hello-17194 → HTTP 200; confirmed persisted in MySQL
• /providers and /dois listing endpoints serve indexed data from OpenSearch

lupo_api_dev_server_demo.mp4

/providers showing the created organization
/dois listing served from OpenSearch

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