[refactor] Centralize filesystem entry classification in inventory flow

[paul-fresquet]

Summary:

• Centralize file system entry type detection behind IFileSystemInspector with a new ClassifyEntry(FileSystemInfo) method.
• Keep FileSystemEntryKind in the client layer (no move to Common) and preserve existing inventory behavior.

Key changes:

• Added ClassifyEntry to IFileSystemInspector and implemented it in FileSystemInspector.
• Implemented classification order: symlink detection (LinkTarget + ReparsePoint fallback), POSIX classification (Linux/macOS), then Directory/RegularFile fallback, then Unknown.
• Refactored InventoryBuilder to use FileSystemInspector.ClassifyEntry instead of scattered symlink/POSIX checks.
• Updated InventoryBuilderInspectorTests to the new centralized classifier contract.
• Added FileSystemInspectorTests to cover standard classification and edge behavior.

Notes/risks:

• Existing boolean inspector methods remain functional (non-breaking intent).
• Local targeted inventory unit tests are green after refactor.
• Full solution tests still show a pre-existing failure in ByteSync.Functions.IntegrationTests end-to-end setup (outside this change scope).

[sonarqubecloud]

Quality Gate passed

Issues
8 New issues
0 Accepted issues

Measures
0 Security Hotspots
82.7% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[Copilot]

Pull request overview

This PR refactors the inventory-building flow to centralize filesystem entry type detection behind IFileSystemInspector.ClassifyEntry(FileSystemInfo), consolidating symlink and POSIX-type handling so InventoryBuilder no longer performs scattered checks.

Changes:

• Added ClassifyEntry(FileSystemInfo) to IFileSystemInspector and implemented it in FileSystemInspector (symlink → POSIX → dir/file fallback → unknown).
• Refactored InventoryBuilder to use FileSystemInspector.ClassifyEntry(...) for skip decisions (symlink + POSIX special files).
• Updated/added unit tests: refactored InventoryBuilderInspectorTests mocks and introduced FileSystemInspectorTests.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests/ByteSync.Client.UnitTests/Services/Inventories/InventoryBuilderInspectorTests.cs	Updates mocks to support the new ClassifyEntry contract and adjusts skip-path tests accordingly.
tests/ByteSync.Client.UnitTests/Services/Inventories/FileSystemInspectorTests.cs	Adds coverage for the new centralized classification logic (directory/file/symlink/POSIX special/null).
src/ByteSync.Client/Services/Inventories/InventoryBuilder.cs	Replaces direct POSIX + reparse-point checks with centralized ClassifyEntry calls and removes now-redundant helper methods.
src/ByteSync.Client/Services/Inventories/FileSystemInspector.cs	Implements ClassifyEntry and introduces internal POSIX classifier wiring plus link-target/reparse-point helpers.
src/ByteSync.Client/Interfaces/Controls/Inventories/IFileSystemInspector.cs	Extends inspector interface with ClassifyEntry.

Comments suppressed due to low confidence (1)

src/ByteSync.Client/Services/Inventories/InventoryBuilder.cs:406

• Symlink/reparse-point skips no longer emit any log message (previously IsReparsePoint(...) logged warnings). This reduces observability when inventories unexpectedly skip content. Consider adding a warning/info log when ClassifyEntry(...) returns Symlink (either here or inside the classifier), consistent with other skip reasons.

        var entryKind = FileSystemInspector.ClassifyEntry(fileInfo);
        if (entryKind == FileSystemEntryKind.Symlink)
        {
            RecordSkippedEntry(inventoryPart, fileInfo, SkipReason.Symlink, FileSystemEntryKind.Symlink);
            
            return true;

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[Copilot]

In ClassifyEntry, the POSIX classification catch returns Unknown immediately. That short-circuits the intended fallback to Directory/RegularFile classification and can change behavior if the POSIX classifier throws. Consider swallowing/logging the exception and continuing to the type-based fallback instead of returning early.

Suggested change

	return FileSystemEntryKind.Unknown;
	// Ignore POSIX classification failures and fall back to type-based classification below.

[Copilot]

ClassifyEntry defensively handles null inputs, but the interface contract uses a non-nullable FileSystemInfo parameter. With nullable enabled, consider changing the signature to FileSystemInfo? to reflect the supported input and avoid callers needing null! in tests.

Suggested change

	FileSystemEntryKind ClassifyEntry(FileSystemInfo fsi);
	FileSystemEntryKind ClassifyEntry(FileSystemInfo? fsi);