Update DB_URL format in downloader

[areguig]

The DB_URL environment variable passed to typetype-downloader was using a JDBC connection string (jdbc:postgresql://...), but the downloader is a Go service that expects a standard PostgreSQL DSN (postgres://...). This caused the service to crash on startup.

[Priveetee]

Thanks for catching this.

The direction looks right: the downloader is a Go service, so it should not receive a JDBC URL.

Before merging, could you also update docker-compose.dev.yml? It still passes:

DB_URL: jdbc:postgresql://postgres:5432/typetype_downloader

so the same startup issue would remain in the dev/beta compose stack.

One small consistency point too: after moving credentials into DB_URL, DB_USER and DB_PASSWORD are still set separately to typetype. If the downloader reads DB_URL first, those become redundant or potentially misleading. I think we should either remove them or align them with the same env vars used in DB_URL.

Expected shape would be something like:

DB_URL: postgres://${DATABASE_USER:-typetype}:${DATABASE_PASSWORD:-typetype}@postgres:5432/typetype_downloader

applied consistently to both production and dev compose files.