feat(tui): add usage overlay and sidebar for displaying usage statistics and tasks

feat(tui): implement status bar with connection and turn state indicators
feat(tui): create workflow panel for agent status and progress visualization
feat(web): introduce web frontend interface with static file serving
feat(ws): add WebSocket interface for real-time communication and session management

apps/application/src/auth/mod.rs

@@ -0,0 +1,16 @@
+//! Auth use-case implementations.
+//!
+//! Contains concrete service types that implement the domain's
+//! authentication and session management traits by coordinating
+//! injected repository and port dependencies.
+//!
+//! # Use Cases
+//!
+//! - [`oauth_service`] — `OAuthUseCase`: OAuth 2.0 authorization-code + PKCE flow
+//! - [`session_service`] — `SessionServiceImpl`: session CRUD lifecycle
+
+pub mod oauth_service;
+pub mod session_service;
+
+pub use oauth_service::{OAuthFlowStore, OAuthUseCase, TokenExchanger};
+pub use session_service::SessionServiceImpl;