Setup docs drift: 7 docker-compose services not mentioned in README

Setup doc drift found

Running a scan that compares docker-compose.yml against README docs to find gaps that break local setup.

Finding — Services not documented docker-compose.yml defines 7 services (app, app_spark, database, lsp, py, server, server_spark) but README has no mention of docker compose up. Engineer clones repo, follows docs, nothing starts.

Proposed patch — add to Setup section:

docker compose up -d

Services started: app, app_spark, database, lsp, py, server, server_spark

Confidence: HIGH. Happy to open a PR if useful.