Fixed Directory Enumeration

[i2h3]

• Our corporate instance was a real world use case in which the retrieved metadata of a directory and its content is no longer fulfilling the previous assumption that the first item is related to the queried directory itself. Instead, it can be anywhere in the array. Hence the implementation had to be changed to detect it by other means while taking the special __NC_ROOT__ case into consideration.
• While reading, I also applied code style changes based on conventional Swift code style.
• Further, I hope to improve clarity by renaming some symbols like DirectoryReadConversionActor to DirectoryMetadataContainer which hints its purpose a lot better in my opinion.
• Also replaced some occurrences of empty strings or __NC_ROOT__ literals with the symbol reference to NextcloudKit.

[Copilot]

Pull Request Overview

Aligns directory enumeration with WebDAV semantics and NextcloudKit conventions, and refactors metadata conversion to reliably identify the enumerated directory.

• Replace toDirectoryReadMetadatas with toSendableDirectoryMetadata and introduce isDirectoryToRead to correctly identify the target directory among NKFile entries.
• Normalize root handling to use NextcloudKit.shared.nkCommonInstance.rootFileName and switch tests to davFilesUrl.
• Update mock interfaces and tests to reflect the new behavior and expectations.

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
Sources/NextcloudFileProviderKit/Extensions/NKFile+Extensions.swift	Adds isDirectoryToRead and toSendableDirectoryMetadata; adjusts root fix-up in toItemMetadata; introduces an actor container for concurrent conversion.
Sources/NextcloudFileProviderKit/Enumeration/Enumerator+SyncEngine.swift	Switches to new conversion API and improves logging; ensures directory metadata is inserted for DB updates.
Sources/NextcloudFileProviderKit/Item/Item+Create.swift	Uses toSendableDirectoryMetadata during item creation; updates logging and variables.
Tests/NextcloudFileProviderKitTests/NKFileExtensionTests.swift	Updates and adds tests for root handling, directory identification, and new conversion API.
Tests/Interface/MockRemoteInterfaceTests.swift	Aligns expectations with NextcloudKit root naming and WebDAV path.
Tests/Interface/MockRemoteItem.swift	Adjusts root name and NKFile mapping; potential regression in serverUrl mapping for non-root items.
Tests/InterfaceTests/MockRemoteInterfaceTests.swift	Imports NextcloudKit and updates assertions for root file naming.
Tests/NextcloudFileProviderKitTests/RemoteChangeObserverTests.swift	Uses davFilesUrl in test setup and formats a closure for readability.

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