fix: backup before selfplay, never rmtree — crash-safe

rmtree(training_data) → mv to training_data_prev
训练成功后再清理backup, 崩了数据不丢

scripts/training_orchestrator.py

@@ -34,7 +34,11 @@ def run(cmd, cwd=HJHA_DIR, to=86400):
 def selfplay(games):
     log(f"── 自对弈 {games}局 ──")
     td = os.path.join(HJHA_DIR, 'training_data')
-    if os.path.exists(td): shutil.rmtree(td)
+    # 先备份旧数据, 崩了也不丢
+    if os.path.exists(td):
+        backup = f"{td}_prev"
+        if os.path.exists(backup): shutil.rmtree(backup)
+        shutil.move(td, backup)
     os.makedirs(td)
     
     env = os.environ.copy()
@@ -293,6 +297,9 @@ def main():
         if not ok:
             log("训练/eval失败! 跳过")
             continue
+        # 训练成功, 清理备份
+        backup = os.path.join(HJHA_DIR, 'training_data_prev')
+        if os.path.exists(backup): shutil.rmtree(backup)
         if wr is not None:
             winrate = wr