feat(config): integrate etcd for service discovery and config management

- Add etcd-client dependency for distributed configuration storage
- Implement EtcdConfig with priority: etcd > environment variables > defaults
- Add ServiceRegistry for service registration with lease keep-alive
- Integrate etcd-based service discovery for appks gRPC connections
- Add service watcher for real-time service instance updates
- Migrate Redis configuration from single URL to cluster node list
- Update Dockerfile with default IMKS_HOST and IMKS_PORT environment variables
- Add etcd bootstrap configuration through environment variables
- Implement Redis cluster URL building with optional authentication

telemetry/traces.rs

@@ -2,9 +2,9 @@
 
 use opentelemetry::trace::TracerProvider as _;
 use opentelemetry_otlp::{Protocol, SpanExporter, WithExportConfig};
+use opentelemetry_sdk::Resource;
 use opentelemetry_sdk::propagation::TraceContextPropagator;
 use opentelemetry_sdk::trace::{SdkTracerProvider, Tracer};
-use opentelemetry_sdk::Resource;
 use tracing_opentelemetry::OpenTelemetryLayer;
 use tracing_subscriber::Registry;
 
@@ -24,9 +24,7 @@ fn build_span_exporter(config: &TelemetryConfig) -> ImksResult<SpanExporter> {
             .with_protocol(Protocol::HttpBinary)
             .with_endpoint(&config.otlp_endpoint)
             .build()
-            .map_err(|e| {
-                crate::ImksError::Internal(format!("OTLP HTTP span exporter: {e}"))
-            }),
+            .map_err(|e| crate::ImksError::Internal(format!("OTLP HTTP span exporter: {e}"))),
     }
 }