Local development
Ports, database, and the health check.
The web app binds to 127.0.0.1 on port 3009 unless that port is taken. The Fastify API binds to 127.0.0.1 on port 3010. The browser talks only to the web origin. A local route forwards /api/platform to the API.
GET http://127.0.0.1:3010/healthPostgreSQL runs on this Mac. Do not point DATABASE_URL at a remote host for this stage.