Refactor user management: Extract IUserService and UserService, consolidate user registration, authentication, and profile management. Fix memory leaks in ApiClient, enhance connection management, and improve error handling in AuthController and UsersController. Update IRC command handling to utilize IUserService for user operations.

docs/changelog/v0.2.8.md

@@ -2,6 +2,9 @@
 
 ## Bug Fixes
 
+- Fix memory leak — `HttpResponseMessage` objects never disposed in `ApiClient`, leaking TCP connections and content buffers on every API call (especially on failed connection attempts)
+- Fix 401 retry leak — `AuthenticatedGetAsync`/`AuthenticatedRequestAsync` leaked the original response when retrying after token refresh
+- Fix connection failure cleanup — `ConnectionManager.ConnectAsync` now properly disposes `ApiClient` and `EchoHubConnection` on any failure path (previously only cleaned up on saved-token auth failures)
 - Fix IRC gateway sending UTF-8 BOM on first message, breaking CAP negotiation and SASL auth for all clients
 - Handle `AUTHENTICATE *` (SASL abort) instead of crashing on invalid base64
 
@@ -10,6 +13,11 @@
 - Add Docker support for EchoHub.Server — `docker compose up -d` for easy self-hosting with persistent volume for database, uploads, and logs
 - IRC account creation — connecting with a new username auto-registers the account (PASS and SASL PLAIN)
 
+## Refactoring
+
+- Extract `IUserService`/`UserService` — consolidate user registration, authentication, and profile management into a dedicated service, eliminating duplicated logic between `AuthController` and `ChatService`
+- IRC gateway now checks ban status during authentication (previously skipped)
+
 ## CI
 
 - Add Docker workflow — builds and pushes multi-arch (`amd64`/`arm64`) server image to GHCR on release