Tests fail on Windows due to path and line ending differences

[denini08]

When running the tests on Windows, some tests fail due to differences in file paths and line endings compared to Linux/macOS. Specifically:

• File paths use backslashes () on Windows instead of forward slashes (/).
• Line endings are \r\n on Windows instead of \n.
• Some error messages containing paths need normalization for cross-platform compatibility.

I will submit a pull request to fix this in a way that works on all platforms without breaking existing behavior.