Custom providers update (#4099)

Co-authored-by: developerayo <shodipovi@gmail.com>
Co-authored-by: Douwe Osinga <douwe@squareup.com>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Zane Staggs <zane@squareup.com>

crates/goose/src/config/mod.rs

@@ -1,4 +1,5 @@
 pub mod base;
+pub mod custom_providers;
 mod experiments;
 pub mod extensions;
 pub mod permission;
@@ -6,6 +7,7 @@ pub mod signup_openrouter;
 
 pub use crate::agents::ExtensionConfig;
 pub use base::{Config, ConfigError, APP_STRATEGY};
+pub use custom_providers::CustomProviderConfig;
 pub use experiments::ExperimentManager;
 pub use extensions::{ExtensionConfigManager, ExtensionEntry};
 pub use permission::PermissionManager;