Configuration is a code registry plus the database

Configuration is not a file written at runtime. One code-level declarative registry (the single source of truth) defines every setting: default, ranges and validation, type, docs, tests and allowed scopes. Changed values are written to the database, never to a config file. Scopes: admin/global (admins only), user, and project/conversation; a setting may allow several, and resolution is layered (UD-C1). Adding, editing or deleting a setting is easy and mechanical; the settings UI is generated from the registry. The bootstrap tier (needed before the database exists) and repository tooling configuration stay checked-in files.