Refactor CMS and IAM modules: restructure presentation and command layers

- Removed HTTP adapter module from CMS infrastructure.
- Updated CMS infrastructure module to exclude HTTP.
- Introduced presentation layer in CMS with DTOs and handlers for REST API.
- Added command types for CMS domain operations to encapsulate input data.
- Created typed error handling for CMS presentation layer.
- Implemented handlers for CMS REST API endpoints.
- Removed HTTP DTOs and handlers from IAM infrastructure.
- Introduced command types for IAM domain operations.
- Created presentation layer in IAM with DTOs and handlers for OAuth flow.
- Implemented typed error handling for IAM presentation layer.

crates/zesdex-cms/src/domain/mod.rs

@@ -19,6 +19,7 @@
 //! They contain no I/O, no framework imports, and no side effects.
 
 pub mod app_config;
+pub mod commands;
 pub mod conversation;
 pub mod edit_log;
 pub mod error;