[sgl-router] refactor - move policy-required states under src/state (#40272)

Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>

experimental/sgl-router/tests/component/discovery/static_urls.rs

@@ -90,7 +90,8 @@ async fn static_urls_pd_role_resolved_end_to_end() {
     use axum::{routing::get, Json, Router};
     use serde_json::json;
     use sgl_router::config::{
-        ActiveLoadConfig, Config, DiscoveryBackend, ObservabilityConfig, ProxyConfig, ServerConfig,
+        Config, DiscoveryBackend, InflightLoadConfig, ObservabilityConfig, ProxyConfig,
+        ServerConfig,
     };
     use sgl_router::discovery::{spawn_discovery, WorkerId};
     use sgl_router::workers::{manager, WorkerRegistry};
@@ -146,7 +147,7 @@ async fn static_urls_pd_role_resolved_end_to_end() {
             urls: vec![url.clone()],
         }),
         proxy: ProxyConfig::default(),
-        active_load: ActiveLoadConfig::default(),
+        router_inflight_load: InflightLoadConfig::default(),
     };
 
     let registry = Arc::new(WorkerRegistry::default());