fix: Correct module paths and conditional compilation for magic feature

Co-authored-by: aider (openai/andrew/openrouter/sonoma-sky-alpha) <aider@aider.chat>

src/modes/diff.rs

@@ -171,6 +171,7 @@ fn spawn_writer_thread(
     compression_type: crate::compression_engine::CompressionType,
     fd_write: libc::c_int,
 ) -> std::thread::JoinHandle<Result<(), anyhow::Error>> {
+    #[allow(unsafe_code)]
     let pipe_writer_raw = unsafe { std::fs::File::from_raw_fd(fd_write) };
     std::thread::spawn(move || {
         write_item_to_pipe(item_path, compression_type, pipe_writer_raw)