Evaluate @unchecked Sendable usage in XcodeOutputProcessor

[diogot]

Summary

The XcodeOutputProcessor class uses @unchecked Sendable as a workaround because XCBeautifier from XcbeautifyLib does not conform to Sendable.

Current Implementation

The class is marked as @unchecked Sendable with the XCBeautifier stored as a private property.

Concern

A PR review comment suggested using @MainActor instead to provide proper isolation. However, for a CLI tool, @MainActor may not be appropriate as it would require all callers to be on the main actor.

Options to Evaluate

1. Keep @unchecked Sendable - Current approach, safe if XCBeautifier.format(line:) is synchronous and the processor is only accessed from a single task
2. Use @mainactor - Provides compiler-enforced isolation but may not be suitable for CLI tools
3. Make it an actor - Provides proper isolation with async access
4. Verify XCBeautifier thread safety - If the library is thread-safe, @unchecked Sendable is correct

References

• PR comment: Integrate xcbeautify as Swift library and misc fixes #39
• File: Sources/Xproject/Utilities/XcodeOutputProcessor.swift