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/application/services/file_retrieval_service.rs

@@ -7,10 +7,12 @@ use crate::application::dtos::file_dto::FileDto;
 use crate::application::ports::file_ports::{FileRetrievalUseCase, OptimizedFileContent};
 use crate::application::ports::storage_ports::FileReadPort;
 use crate::common::errors::DomainError;
-use tracing::{debug, info};
 use crate::infrastructure::repositories::pg::file_blob_read_repository::FileBlobReadRepository;
 use crate::infrastructure::services::file_content_cache::FileContentCache;
-use crate::infrastructure::services::image_transcode_service::{ImageTranscodeService, OutputFormat};
+use crate::infrastructure::services::image_transcode_service::{
+    ImageTranscodeService, OutputFormat,
+};
+use tracing::{debug, info};
 
 /// Threshold below which files are served from RAM cache (10 MB).
 const CACHE_THRESHOLD: u64 = 10 * 1024 * 1024;