fixup! Add OTLP-only observability controls

Author: sl5-guy

README.md

@@ -46,12 +46,7 @@ Copy `config.example.toml` to `config.toml` and edit it. Key sections:
 | `otlp_endpoint` | no | OTLP gRPC endpoint for distributed tracing |
 
 Set `AGENT_GATEWAY_LOG_STDOUT=false` to disable stdout/stderr formatting while
-leaving OTLP export enabled. The sidecar reads observability settings from
-environment variables. Use `RUST_LOG` for its tracing filter and set
-`OTEL_EXPORTER_OTLP_ENDPOINT` (for example, `http://localhost:4317`) to export
-sidecar spans over OTLP. When enabled, the sidecar injects W3C trace-context
-headers into the CONNECT request it sends to the gateway, and the gateway
-continues the same trace.
+leaving OTLP export enabled.
 
 ## Running