Function is_transient_windows_file_lock

src/sync.rs:78–85

True for Windows errors that indicate another process is briefly holding the file: `ERROR_SHARING_VIOLATION` (32) and `ERROR_LOCK_VIOLATION` (33) map through as raw OS errors, while Defender-style scans surface as plain `PermissionDenied` (`ERROR_ACCESS_DENIED`, os error 5).

(err: &std::io::Error)

/// map through as raw OS errors, while Defender-style scans surface as plain
/// `PermissionDenied` (`ERROR_ACCESS_DENIED`, os error 5).
fn is_transient_windows_file_lock(err: &std::io::Error) -> bool {
    const ERROR_SHARING_VIOLATION: i32 = 32;
    const ERROR_LOCK_VIOLATION: i32 = 33;
    matches!(
        err.raw_os_error(),
        Some(ERROR_SHARING_VIOLATION | ERROR_LOCK_VIOLATION)
    ) || err.kind() == std::io::ErrorKind::PermissionDenied
}

/// Get filesystem mtime (seconds since epoch) and size for pre-filter.
pub fn file_stat(path: &Path) -> Option<(i64, u64)> {