fix: restore provider and extensions for LRU-evicted sessions (aaif-goose#7616)

Author: wpfleger96

crates/goose/src/execution/manager.rs

@@ -95,10 +95,30 @@ impl AgentManager {
             GoosePlatform::GooseDesktop,
         );
         let agent = Arc::new(Agent::with_config(config));
-        if let Some(provider) = &*self.default_provider.read().await {
-            agent
-                .update_provider(Arc::clone(provider), &session_id)
-                .await?;
+
+        if let Ok(session) = self.session_manager.get_session(&session_id, false).await {
+            if session.provider_name.is_some() {
+                info!(
+                    "Restoring evicted session {} (provider: {:?})",
+                    session_id, session.provider_name
+                );
+                if let Err(e) = agent.restore_provider_from_session(&session).await {
+                    tracing::warn!(
+                        "Failed to restore provider for session {}: {}",
+                        session_id,
+                        e
+                    );
+                }
+            }
+            agent.load_extensions_from_session(&session).await;
+        }
+
+        if agent.provider().await.is_err() {
+            if let Some(provider) = &*self.default_provider.read().await {
+                agent
+                    .update_provider(Arc::clone(provider), &session_id)
+                    .await?;
+            }
         }
 
         let mut sessions = self.sessions.write().await;