acp: Fix model selector sometimes showing no models (#36995)

Release Notes:

- N/A

crates/agent2/src/agent.rs

@@ -61,16 +61,19 @@ pub struct LanguageModels {
     model_list: acp_thread::AgentModelList,
     refresh_models_rx: watch::Receiver<()>,
     refresh_models_tx: watch::Sender<()>,
+    _authenticate_all_providers_task: Task<()>,
 }
 
 impl LanguageModels {
-    fn new(cx: &App) -> Self {
+    fn new(cx: &mut App) -> Self {
         let (refresh_models_tx, refresh_models_rx) = watch::channel(());
+
         let mut this = Self {
             models: HashMap::default(),
             model_list: acp_thread::AgentModelList::Grouped(IndexMap::default()),
             refresh_models_rx,
             refresh_models_tx,
+            _authenticate_all_providers_task: Self::authenticate_all_language_model_providers(cx),
         };
         this.refresh_list(cx);
         this
@@ -150,6 +153,52 @@ impl LanguageModels {
     fn model_id(model: &Arc<dyn LanguageModel>) -> acp_thread::AgentModelId {
         acp_thread::AgentModelId(format!("{}/{}", model.provider_id().0, model.id().0).into())
     }
+
+    fn authenticate_all_language_model_providers(cx: &mut App) -> Task<()> {
+        let authenticate_all_providers = LanguageModelRegistry::global(cx)
+            .read(cx)
+            .providers()
+            .iter()
+            .map(|provider| (provider.id(), provider.name(), provider.authenticate(cx)))
+            .collect::<Vec<_>>();
+
+        cx.background_spawn(async move {
+            for (provider_id, provider_name, authenticate_task) in authenticate_all_providers {
+                if let Err(err) = authenticate_task.await {
+                    if matches!(err, language_model::AuthenticateError::CredentialsNotFound) {
+                        // Since we're authenticating these providers in the
+                        // background for the purposes of populating the
+                        // language selector, we don't care about providers
+                        // where the credentials are not found.
+                    } else {
+                        // Some providers have noisy failure states that we
+                        // don't want to spam the logs with every time the
+                        // language model selector is initialized.
+                        //
+                        // Ideally these should have more clear failure modes
+                        // that we know are safe to ignore here, like what we do
+                        // with `CredentialsNotFound` above.
+                        match provider_id.0.as_ref() {
+                            "lmstudio" | "ollama" => {
+                                // LM Studio and Ollama both make fetch requests to the local APIs to determine if they are "authenticated".
+                                //
+                                // These fail noisily, so we don't log them.
+                            }
+                            "copilot_chat" => {
+                                // Copilot Chat returns an error if Copilot is not enabled, so we don't log those errors.
+                            }
+                            _ => {
+                                log::error!(
+                                    "Failed to authenticate provider: {}: {err}",
+                                    provider_name.0
+                                );
+                            }
+                        }
+                    }
+                }
+            }
+        })
+    }
 }
 
 pub struct NativeAgent {