feat(routing): consolidate scheduling strategy configuration

apps/aether-gateway/src/handlers/admin/model/routing.rs

@@ -67,11 +67,14 @@ pub(crate) async fn build_admin_global_model_routing_payload(
             .push(key);
     }
 
-    // Effective default scheduling: system-default routing group first, then
-    // legacy system-config keys.
-    let ordering_config = crate::scheduler::config::read_scheduler_ordering_config(state.app())
-        .await
-        .unwrap_or_default();
+    // The admin view reports the system-default routing strategy.
+    let ordering_config =
+        match crate::scheduler::config::read_system_default_routing_ordering_config(state.app())
+            .await
+        {
+            Ok(Some(config)) => config,
+            Ok(None) | Err(_) => crate::scheduler::config::SchedulerOrderingConfig::default(),
+        };
     let scheduling_mode = ordering_config.scheduling_mode_str().to_string();
     let priority_mode = ordering_config.priority_mode_str().to_string();
     let keep_priority_on_conversion = ordering_config.keep_priority_on_conversion;

apps/aether-gateway/src/handlers/admin/observability/monitoring/cache_store.rs

@@ -265,7 +265,9 @@ pub(super) async fn build_admin_monitoring_cache_snapshot(
     state: &AdminAppState<'_>,
 ) -> Result<AdminMonitoringCacheSnapshot, GatewayError> {
     let ordering_config =
-        crate::scheduler::config::read_scheduler_ordering_config(state.app()).await?;
+        crate::scheduler::config::read_system_default_routing_ordering_config(state.app())
+            .await?
+            .unwrap_or_default();
     let scheduling_mode = ordering_config.scheduling_mode_str().to_string();
     let provider_priority_mode = ordering_config.priority_mode_str().to_string();
 

apps/aether-gateway/src/handlers/admin/routing/mod.rs

@@ -44,6 +44,8 @@ struct AdminRoutingGroupCreateRequest {
     #[serde(default)]
     is_system_default: bool,
     #[serde(default)]
+    sort_order: i64,
+    #[serde(default)]
     config_json: Option<Value>,
 }
 
@@ -137,6 +139,7 @@ async fn maybe_build_routing_groups_response(
                 description: payload.description,
                 enabled: payload.enabled,
                 is_system_default: payload.is_system_default,
+                sort_order: payload.sort_order,
                 config_json,
                 version: 1,
                 created_at: now,
@@ -464,6 +467,9 @@ fn build_routing_group_update_patch(
     if let Some(value) = object.get("is_system_default") {
         patch.is_system_default = Some(required_bool(value, "is_system_default")?);
     }
+    if let Some(value) = object.get("sort_order") {
+        patch.sort_order = Some(required_i64(value, "sort_order")?.max(0));
+    }
     if let Some(value) = object.get("config_json") {
         validate_config_json(value)?;
         patch.config_json = Some(value.clone());
@@ -604,6 +610,7 @@ fn routing_group_payload(group: &StoredRoutingGroup) -> Value {
         "description": group.description,
         "enabled": group.enabled,
         "is_system_default": group.is_system_default,
+        "sort_order": group.sort_order,
         "config_json": group.config_json,
         "version": group.version,
         "created_at": group.created_at,

apps/aether-gateway/src/handlers/proxy/mod.rs

@@ -68,7 +68,6 @@ use crate::scheduler::candidate::{
     is_auth_api_key_concurrency_limit_skip_reason, AUTH_API_KEY_CONCURRENCY_LIMIT_SKIP_REASON,
     LEGACY_API_KEY_CONCURRENCY_LIMIT_SKIP_REASON,
 };
-use crate::scheduler::config::{read_scheduler_ordering_config, SchedulerSchedulingMode};
 use crate::stage_metrics::observe_gateway_stage_ms;
 use crate::{
     AppState, FrontdoorUserRpmOutcome, GatewayError, GatewayFallbackMetricKind,
@@ -411,27 +410,7 @@ async fn maybe_forward_public_request_to_tunnel_owner(
             policy_context,
         )
     } else {
-        let cache_affinity_enabled = match read_scheduler_ordering_config(state).await {
-            Ok(config) => config.scheduling_mode == SchedulerSchedulingMode::CacheAffinity,
-            Err(err) => {
-                warn!(
-                    trace_id = %request_context.trace_id,
-                    error = ?err,
-                    "gateway failed to load scheduler config while checking tunnel affinity forwarding mode"
-                );
-                SchedulerSchedulingMode::default() == SchedulerSchedulingMode::CacheAffinity
-            }
-        };
-        if !cache_affinity_enabled {
-            return Ok(None);
-        }
-        crate::scheduler::affinity::read_cached_scheduler_affinity_target(
-            state,
-            &auth_context.api_key_id,
-            affinity_context.client_session_affinity.as_ref(),
-            api_format,
-            &affinity_context.requested_model,
-        )
+        return Ok(None);
     };
     let Some(target) = target else {
         return Ok(None);