fix(writer): 使用哨兵值标记资源转存失败，避免重复处理

- 引入
- 修改查询条件，将 platform_song_id 为空视为未导入状态
- 在标记资源转存失败时，将 platform_song_id 设置为哨兵值 -1
- 更新测试用例，验证 platform_song_id 字段的正确更新及查询条件调整
- 删除旧的 resource_transfer_failed 字符串常量及相关引用

@@ -3,7 +3,8 @@ import uuid
 _SINGER_INDEX_VALUES = set('ABCDEFGHIJKLMNOPQRSTUVWXYZ#')
 _SINGER_SEX_VALUES = {'M', 'F', 'C', 'U'}
 _SINGER_AREA_VALUES = {'华语', '欧美', '韩国', '日本', '其他'}
-RESOURCE_TRANSFER_FAILED = 'resource_transfer_failed'
+# 资源转存失败哨兵值：platform_song_id 设为 -1 表示 OSS 失败，区别于 NULL（待导入）和正整数（成功）
+PLATFORM_SONG_ID_RESOURCE_FAILED = -1
 
 
 def _singer_index(value) -> str:
@@ -50,11 +51,11 @@ def fetch_pending_yinyan_song_records(cur, limit: int) -> list[dict]:
         FROM yinyan_song_records
         WHERE is_yinyan_push = FALSE
           AND platform IS NOT NULL
-          AND COALESCE(recording_id, '') != %s
+          AND platform_song_id IS NULL
         ORDER BY song_id
         LIMIT %s
         """,
-        (RESOURCE_TRANSFER_FAILED, limit),
+        (limit,),
     )
     rows = cur.fetchall()
     return [{'song_id': row[0], 'record_id': row[1], 'platform': row[2]} for row in rows]
@@ -210,14 +211,14 @@ def delete_qq_song_and_yinyan_record(cur, song_id: int, platform_song_id: int, s
 
 
 def mark_yinyan_record_resource_failed(cur, song_id: int, record_id: int, platform: str) -> None:
-    """保留未导入状态，并标记资源转存失败，避免后续批次重复处理。"""
+    """保留未导入状态，并将 platform_song_id 置为哨兵值 -1，避免后续批次重复处理。"""
     cur.execute(
         """
         UPDATE yinyan_song_records
-        SET is_yinyan_push = FALSE, recording_id = %s
+        SET is_yinyan_push = FALSE, platform_song_id = %s
         WHERE song_id = %s AND record_id = %s AND platform = %s AND is_yinyan_push = FALSE
         """,
-        (RESOURCE_TRANSFER_FAILED, song_id, record_id, platform),
+        (PLATFORM_SONG_ID_RESOURCE_FAILED, song_id, record_id, platform),
     )
 
 

@@ -68,8 +68,8 @@ def test_mark_yinyan_record_resource_failed_keeps_unpushed_state_and_excludes_re
     sql, params = cur.execute.call_args[0]
     assert 'UPDATE yinyan_song_records' in sql
     assert 'is_yinyan_push = FALSE' in sql
-    assert 'recording_id = %s' in sql
-    assert params == ('resource_transfer_failed', 10, 100, '1')
+    assert 'platform_song_id = %s' in sql
+    assert params == (-1, 10, 100, '1')
 
 
 def test_upsert_qq_singers_empty_does_nothing():
@@ -144,7 +144,8 @@ def test_fetch_pending_yinyan_song_records_reads_platform_for_single_platform_im
     sql, params = cur.execute.call_args[0]
     assert 'SELECT song_id, record_id, platform' in sql
     assert 'platform IS NOT NULL' in sql
-    assert params == ('resource_transfer_failed', 500)
+    assert 'platform_song_id IS NULL' in sql
+    assert params == (500,)
     assert rows == [
         {'song_id': 10, 'record_id': 100, 'platform': '1'},
         {'song_id': 11, 'record_id': 101, 'platform': '2'},