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/application/src/config.rs

@@ -0,0 +1,13 @@
+#[derive(Clone)]
+pub struct AppConfig {
+    pub allow_registration: bool,
+}
+
+impl AppConfig {
+    pub fn from_env() -> Self {
+        let allow_registration = std::env::var("ALLOW_REGISTRATION")
+            .map(|v| v == "true" || v == "1")
+            .unwrap_or(false);
+        Self { allow_registration }
+    }
+}