[router] add py binding and readme for openai router and history backend (#11453)

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

sgl-router/src/routers/openai/router.rs

@@ -27,7 +27,7 @@ use std::{
 };
 use tokio::sync::mpsc;
 use tokio_stream::wrappers::UnboundedReceiverStream;
-use tracing::{info, warn};
+use tracing::warn;
 
 // Import from sibling modules
 use super::conversations::{
@@ -197,6 +197,11 @@ impl OpenAIRouter {
                 Ok(r) => r,
                 Err(e) => {
                     self.circuit_breaker.record_failure();
+                    tracing::error!(
+                        url = %url,
+                        error = %e,
+                        "Failed to forward request to OpenAI"
+                    );
                     return (
                         StatusCode::BAD_GATEWAY,
                         format!("Failed to forward request to OpenAI: {}", e),
@@ -518,12 +523,6 @@ impl crate::routers::RouterTrait for OpenAIRouter {
     ) -> Response {
         let url = format!("{}/v1/responses", self.base_url);
 
-        info!(
-            requested_store = body.store,
-            is_streaming = body.stream,
-            "openai_responses_request"
-        );
-
         // Validate mutually exclusive params: previous_response_id and conversation
         // TODO: this validation logic should move the right place, also we need a proper error message module
         if body.previous_response_id.is_some() && body.conversation.is_some() {