feat(auth): implement JWT authentication and user registration

- Added JWT authentication with token generation and validation.
- Introduced user registration functionality with email and password.
- Integrated Argon2 for password hashing.
- Created SQLite user repository for user data persistence.
- Updated application context to include user repository and configuration settings.
- Added environment variable support for JWT secret and registration allowance.
- Enhanced error handling for unauthorized access and validation errors.
- Updated presentation layer to handle login and registration requests.

crates/domain/src/errors.rs

@@ -13,4 +13,7 @@ pub enum DomainError {
 
     #[error("Infrastructure failure: {0}")]
     InfrastructureError(String),
+
+    #[error("Unauthorized: {0}")]
+    Unauthorized(String),
 }