Declarative Configuration Conventions

The file replaces properties and env vars — not code

Declarative YAML supersedes scattered otel.* properties, -Dotel.* flags, and SDK-setting OTEL_* variables. It does not supersede SDK components registered through code: SpanProcessors (e.g. an attribute-stripping processor that removes url.query/url.full), custom samplers, and other SPI-registered components keep working alongside the file and stay where they are. When migrating a service to declarative config, inventory the code-registered components first — each one either has a schema-supported equivalent (move it) or it does not (keep the code); deleting one because "everything is YAML now" silently removes the guarantee it enforced.

Two facts make this failure silent: