Set PYTHONUNBUFFERED environment variable to ensure unbuffered Python output

src-tauri/src/main.rs

@@ -444,6 +444,7 @@ async fn generate_map(
                 &mut log_file,
                 format!("  program: {}", python.to_string_lossy()),
             );
+            write_log_line(&mut log_file, "  env: PYTHONUNBUFFERED=1");
             for arg in &args {
                 write_log_line(&mut log_file, format!("  arg: {arg}"));
             }
@@ -451,6 +452,7 @@ async fn generate_map(
 
             let mut cmd = Command::new(&python);
             cmd.current_dir(&root)
+                .env("PYTHONUNBUFFERED", "1")
                 .stdout(Stdio::piped())
                 .stderr(Stdio::piped());
             for arg in &args {