1. Old system (Firestore)
Read onlySettings are read from the Firestore project the .NET applications use, with a Google service-account key (the same kind of file as their creds.json). The key is kept on this server in credentials/firestore.json, outside the web pages and git. Nothing is ever written back to Firestore.
2. Channel
Each channel is a collection in Firestore with a document per application. PLAYOUT, SCTE_INFO and FILEMON are read for the settings below; MONITORING is shown for reference. The channel you apply from is saved in config.json (migration).