Newtypes and broker refactor

Reviewed-on: #10

notes-domain/src/lib.rs

@@ -7,12 +7,14 @@
 //! - **Errors**: Domain-specific error types
 //! - **Repositories**: Port traits defining data access interfaces
 //! - **Services**: Use cases orchestrating business logic
+//! - **Value Objects**: Validated newtypes for domain primitives
 
 pub mod entities;
 pub mod errors;
 pub mod ports;
 pub mod repositories;
 pub mod services;
+pub mod value_objects;
 
 // Re-export commonly used types at crate root
 pub use entities::{MAX_TAGS_PER_NOTE, Note, NoteFilter, NoteVersion, Tag, User};
@@ -20,3 +22,7 @@ pub use errors::{DomainError, DomainResult};
 pub use ports::MessageBroker;
 pub use repositories::{NoteRepository, TagRepository, UserRepository};
 pub use services::{CreateNoteRequest, NoteService, TagService, UpdateNoteRequest, UserService};
+pub use value_objects::{
+    Email, MAX_NOTE_TITLE_LENGTH, MAX_TAG_NAME_LENGTH, MIN_PASSWORD_LENGTH, NoteTitle, Password,
+    TagName, ValidationError,
+};