fix(repair): Codex 审查修正 — progress 完成判据加严 + load_progress 防御增强

1. 保存 progress 前重新 detect_issues，只有 empty_field 清零才记 finished
   （修复 L2/L1 空字段被检测但未修复仍写 finished 的问题）
2. load_progress 增加 AttributeError 捕获（防 JSON 非 dict 形态崩溃）

tools/repair_trees.py

@@ -80,7 +80,7 @@ def load_progress(path: Path) -> set[str]:
     try:
         data = json.loads(path.read_text(encoding="utf-8"))
         return set(data.get("finished_video_ids", []))
-    except (json.JSONDecodeError, KeyError, TypeError):
+    except (json.JSONDecodeError, KeyError, TypeError, AttributeError):
         logger.warning("progress 文件损坏，忽略: {}", path)
         return set()
 
@@ -390,9 +390,18 @@ async def main_async(args: argparse.Namespace) -> None:
                 all_stats.append(stats)
                 completed += 1
 
-            # 无 error 且非 dry_run 才记 finished
+            # 修复后重新检测，关键 issue 清零才记 finished
             if stats["error"] is None and not args.dry_run:
-                await save_progress(progress_path, progress_lock, vid)
+                index = TreeIndex.load_json(str(tree_path))
+                remaining = [i for i in detect_issues(index) if i.issue_type == "empty_field"]
+                if not remaining:
+                    await save_progress(progress_path, progress_lock, vid)
+                else:
+                    logger.warning(
+                        "[{}] 修复后仍有 {} 个 empty_field，不计入 finished",
+                        vid,
+                        len(remaining),
+                    )
 
             # 进度日志
             if completed % 10 == 0: