Add logs to model cache (#11551)

codex-rs/core/src/models_manager/manager.rs

@@ -26,6 +26,7 @@ use tokio::sync::RwLock;
 use tokio::sync::TryLockError;
 use tokio::time::timeout;
 use tracing::error;
+use tracing::info;
 
 const MODEL_CACHE_FILE: &str = "models_cache.json";
 const DEFAULT_MODEL_CACHE_TTL: Duration = Duration::from_secs(300);
@@ -216,8 +217,10 @@ impl ModelsManager {
             RefreshStrategy::OnlineIfUncached => {
                 // Try cache first, fall back to online if unavailable
                 if self.try_load_cache().await {
+                    info!("models cache: using cached models for OnlineIfUncached");
                     return Ok(());
                 }
+                info!("models cache: cache miss, fetching remote models");
                 self.fetch_and_update_models().await
             }
             RefreshStrategy::Online => {
@@ -285,13 +288,22 @@ impl ModelsManager {
         let _timer =
             codex_otel::start_global_timer("codex.remote_models.load_cache.duration_ms", &[]);
         let client_version = crate::models_manager::client_version_to_whole();
+        info!(client_version, "models cache: evaluating cache eligibility");
         let cache = match self.cache_manager.load_fresh(&client_version).await {
             Some(cache) => cache,
-            None => return false,
+            None => {
+                info!("models cache: no usable cache entry");
+                return false;
+            }
         };
         let models = cache.models.clone();
         *self.etag.write().await = cache.etag.clone();
         self.apply_remote_models(models.clone()).await;
+        info!(
+            models_count = models.len(),
+            etag = ?cache.etag,
+            "models cache: cache entry applied"
+        );
         true
     }