feat(api): implement user authentication and registration endpoints

- Add main application logic in `api/src/main.rs` to initialize server, database, and services.
- Create authentication routes in `api/src/routes/auth.rs` for login, register, logout, and user info retrieval.
- Implement configuration route in `api/src/routes/config.rs` to expose application settings.
- Define application state management in `api/src/state.rs` to share user service and configuration.
- Set up Docker Compose configuration in `compose.yml` for backend, worker, and database services.
- Establish domain logic in `domain` crate with user entities, repositories, and services.
- Implement SQLite user repository in `infra/src/user_repository.rs` for user data persistence.
- Create database migration handling in `infra/src/db.rs` and session store in `infra/src/session_store.rs`.
- Add necessary dependencies and features in `Cargo.toml` files for both `domain` and `infra` crates.

infra/src/factory.rs

@@ -0,0 +1,54 @@
+use std::sync::Arc;
+
+#[cfg(feature = "sqlite")]
+use crate::SqliteUserRepository;
+use crate::db::DatabasePool;
+use domain::UserRepository;
+
+#[derive(Debug, thiserror::Error)]
+pub enum FactoryError {
+    #[error("Database error: {0}")]
+    Database(#[from] sqlx::Error),
+    #[error("Not implemented: {0}")]
+    NotImplemented(String),
+    #[error("Infrastructure error: {0}")]
+    Infrastructure(#[from] domain::DomainError),
+}
+
+pub type FactoryResult<T> = Result<T, FactoryError>;
+
+pub async fn build_user_repository(pool: &DatabasePool) -> FactoryResult<Arc<dyn UserRepository>> {
+    match pool {
+        #[cfg(feature = "sqlite")]
+        DatabasePool::Sqlite(pool) => Ok(Arc::new(SqliteUserRepository::new(pool.clone()))),
+        #[cfg(feature = "postgres")]
+        DatabasePool::Postgres(pool) => Ok(Arc::new(
+            crate::user_repository::PostgresUserRepository::new(pool.clone()),
+        )),
+        #[allow(unreachable_patterns)]
+        _ => Err(FactoryError::NotImplemented(
+            "No database feature enabled".to_string(),
+        )),
+    }
+}
+
+pub async fn build_session_store(
+    pool: &DatabasePool,
+) -> FactoryResult<crate::session_store::InfraSessionStore> {
+    match pool {
+        #[cfg(feature = "sqlite")]
+        DatabasePool::Sqlite(pool) => {
+            let store = tower_sessions_sqlx_store::SqliteStore::new(pool.clone());
+            Ok(crate::session_store::InfraSessionStore::Sqlite(store))
+        }
+        #[cfg(feature = "postgres")]
+        DatabasePool::Postgres(pool) => {
+            let store = tower_sessions_sqlx_store::PostgresStore::new(pool.clone());
+            Ok(crate::session_store::InfraSessionStore::Postgres(store))
+        }
+        #[allow(unreachable_patterns)]
+        _ => Err(FactoryError::NotImplemented(
+            "No database feature enabled".to_string(),
+        )),
+    }
+}