Redact auth tokens from app-server response logs (#39141)

## Why

App-server response diagnostics can include access tokens returned by the ChatGPT auth refresh flow.

## What changed

- Log successfully parsed server responses instead of raw JSON-RPC response payloads.
- Redact `access_token` from the `Debug` representation of `ChatgptAuthTokensRefreshResponse`.
- Avoid formatting callback send errors that can retain the original response payload.

GitOrigin-RevId: fd47485b38ed89527b25937c759b3273581f6ae6

codex-rs/app-server/src/message_processor.rs

@@ -815,7 +815,6 @@ impl MessageProcessor {
 
     /// Handle a standalone JSON-RPC response originating from the peer.
     pub(crate) async fn process_response(&self, response: JSONRPCResponse) {
-        tracing::info!("<- response: {:?}", response);
         let JSONRPCResponse { id, result, .. } = response;
         self.outgoing.notify_client_response(id, result).await
     }