fix: resolve all clippy warnings and convert integration_tests to custom cfg

- Add type aliases (FileRow, FolderRow, FolderRowPaginated, FolderRowOptUser) to reduce type complexity
- Simplify redundant closures in app_password_handler and webdav_handler
- Remove needless borrow in auth_handler
- Collapse nested if/let chains in login_lockout, webdav_lock, auth, rate_limit
- Box LockEntry in acquire() Err variant to fix large enum variant warning
- Rename DeviceCodeStatus::from_str to parse to avoid should_implement_trait lint
- Add #[allow(clippy::too_many_arguments)] and #[allow(clippy::result_unit_err)] where appropriate
- Convert integration_tests from cargo feature to custom cfg attribute
- Add check-cfg lint config in Cargo.toml for integration_tests cfg

src/interfaces/api/handlers/carddav_handler.rs

@@ -33,9 +33,9 @@ use crate::application::dtos::address_book_dto::{CreateAddressBookDto, UpdateAdd
 use crate::application::dtos::contact_dto::CreateContactVCardDto;
 use crate::application::ports::carddav_ports::{AddressBookUseCase, ContactUseCase};
 use crate::common::di::AppState;
+use crate::infrastructure::adapters::contact_storage_adapter::ContactStorageAdapter;
 use crate::interfaces::errors::AppError;
 use crate::interfaces::middleware::auth::CurrentUser;
-use crate::infrastructure::adapters::contact_storage_adapter::ContactStorageAdapter;
 
 const HEADER_DAV: HeaderName = HeaderName::from_static("dav");