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.

Cargo.toml

@@ -13,6 +13,7 @@ resolver = "2"
 
 [workspace.dependencies]
 tokio = { version = "1.0", features = ["full"] }
+dotenvy = "0.15"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 anyhow = "1.0"