perf: replace dyn trait objects with concrete types to eliminate vtable overhead

Remove async-trait dependency and use native Rust async fn in traits.
Replace Arc<dyn Trait> with Arc<ConcreteType> throughout the codebase
to enable monomorphization and eliminate dynamic dispatch overhead.

Key changes:
- Remove write-behind cache (no implementation existed)
- Fix should_transcode static method call
- Use ContactStorageAdapter directly instead of dyn AddressBookUseCase
- Clean up unused trait imports across services and DI

https://claude.ai/code/session_01EbAFEfyJNLRmJHmmYDX3Tt

src/interfaces/middleware/auth.rs

@@ -11,6 +11,7 @@ use crate::common::di::AppState;
 
 // Re-export CurrentUser from application layer for use in handlers
 pub use crate::application::dtos::user_dto::CurrentUser;
+use crate::application::ports::auth_ports::TokenServicePort;
 
 /// Marker inserted into request extensions when the user was authenticated
 /// via the `oxicloud_access` HttpOnly cookie rather than a Bearer/Basic header.