model routing: cost/latency ranking with ranked fallback list (#849)

crates/brightstaff/src/router/router_model.rs

@@ -1,5 +1,5 @@
-use common::configuration::ModelUsagePreference;
 use hermesllm::apis::openai::{ChatCompletionsRequest, Message};
+use serde::{Deserialize, Serialize};
 use thiserror::Error;
 
 #[derive(Debug, Error)]
@@ -10,6 +10,20 @@ pub enum RoutingModelError {
 
 pub type Result<T> = std::result::Result<T, RoutingModelError>;
 
+/// Internal route descriptor passed to the router model to build its prompt.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct RoutingPreference {
+    pub name: String,
+    pub description: String,
+}
+
+/// Groups a model with its routing preferences (used internally by RouterModelV1).
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ModelUsagePreference {
+    pub model: String,
+    pub routing_preferences: Vec<RoutingPreference>,
+}
+
 pub trait RouterModel: Send + Sync {
     fn generate_request(
         &self,