refactor(chain): _mixins.py 更名 _transfer.py，统一功能域 mixin 命名

TransferChain 的 7 个功能域 mixin 集合文件按域更名 _transfer.py，
与 _recognition/_messaging/_interaction/_music 的单域命名约定对齐；
同步更新 transfer.py 导入、9 个测试文件 patch 目标与架构文档。
另含 chain 基类导入排序优化与未使用导入清理（copy/datetime 已随
dispatch 方法迁入 _messaging.py）。

app/chain/__init__.py

@@ -1,25 +1,26 @@
 from __future__ import annotations
 
-import copy
 import inspect
 import pickle
 import traceback
 from abc import ABCMeta
 from collections.abc import Callable
-from datetime import datetime
 from pathlib import Path
 from typing import Optional, Any, Tuple, List, Set, Union, Dict
 
 from fastapi.concurrency import run_in_threadpool
 
-from app.runtime.cache import FileCache, AsyncFileCache
+from app.application.messaging.message import MessageHelper, MessageQueueManager
+from app.chain._messaging import MessageProcessingMixin, NotificationMixin
+from app.chain._recognition import RecognitionMixin
+from app.db.oper.message import MessageOper
 from app.domain.context import Context, MediaInfo, SubtitleInfo, TorrentInfo
-from app.runtime.events import EventManager
 from app.domain.meta.metabase import MetaBase
+from app.foundation.reflection import ObjectUtils
+from app.runtime.cache import FileCache, AsyncFileCache
+from app.runtime.events import EventManager
 from app.runtime.extensions.module_manager import ModuleManager
 from app.runtime.extensions.plugin_manager import PluginManager
-from app.db.oper.message import MessageOper
-from app.application.messaging.message import MessageHelper, MessageQueueManager
 from app.runtime.log import logger
 from app.schemas import (
     RateLimitExceededException,
@@ -41,9 +42,6 @@ from app.schemas.types import (
     MediaImageType,
     EventType,
 )
-from app.foundation.reflection import ObjectUtils
-from app.chain._messaging import MessageProcessingMixin, NotificationMixin
-from app.chain._recognition import RecognitionMixin
 
 
 class ChainBase(RecognitionMixin, MessageProcessingMixin, NotificationMixin,

app/chain/transfer.py

@@ -57,7 +57,7 @@ from app.schemas.types import (
 from app.runtime.reload import ConfigReloadMixin
 from app.application.transfer import (FailedRetryScheduler, JobManager,
                                       TransferQueue, TransferTask, job_lock)
-from app.chain._mixins import (EpisodeFormatMixin, FailedRetryMixin,
+from app.chain._transfer import (EpisodeFormatMixin, FailedRetryMixin,
                                FileFilterMixin, FileKeyMixin,
                                HistoryMatchMixin, ManualHistoryMixin,
                                ScrapeBatchMixin)

docs/rules/05-architecture.md

@@ -219,7 +219,7 @@ Underscore-prefixed files in `app/chain/` are feature-domain mixins for
 slash-command delegation for `remote_list` / `parse_callback` /
 `handle_callback_interaction` / `handle_text_interaction`), `_music.py`
 (`MusicSubscribeMixin`, the music single/album subscribe domain mixed into
-`SubscribeChain`) and `_mixins.py` (TransferChain feature mixins). A concrete chain that exposes slash-command
+`SubscribeChain`) and `_transfer.py` (TransferChain feature mixins). A concrete chain that exposes slash-command
 interaction inherits `InteractionChainMixin`, injects its handler class via
 `_interaction_handler_type` and implements only `_interaction_handler`; it must
 not re-export application-layer interaction managers.

tests/test_episode_format_helper.py

@@ -722,7 +722,7 @@ def test_transfer_chain_recommend_episode_format_passes_helper_data(monkeypatch)
         lambda item: [sample],
     )
     monkeypatch.setattr(
-        "app.chain._mixins.EpisodeFormatRuleHelper.recommend",
+        "app.chain._transfer.EpisodeFormatRuleHelper.recommend",
         lambda self, rules, sample_files: (True, "", helper_data),
     )
 
@@ -777,7 +777,7 @@ def test_transfer_chain_recommend_episode_format_uses_selected_fileitems(monkeyp
         lambda: [],
     )
     monkeypatch.setattr(
-        "app.chain._mixins.EpisodeFormatRuleHelper.recommend",
+        "app.chain._transfer.EpisodeFormatRuleHelper.recommend",
         lambda self, rules, sample_files: (True, "", {
             **helper_data,
             "received_samples": [item.name for item in sample_files],

tests/test_manual_transfer_history.py

@@ -62,7 +62,7 @@ def _patch_transfer_planning(monkeypatch, chain, fileitem, history, planned, del
         "app.chain.transfer.TransferHistoryOper",
         lambda: history_oper,
     )
-    monkeypatch.setattr("app.chain._mixins.TransferHistoryOper", lambda: history_oper)
+    monkeypatch.setattr("app.chain._transfer.TransferHistoryOper", lambda: history_oper)
     monkeypatch.setattr(
         "app.chain.transfer.DownloadHistoryOper",
         lambda: SimpleNamespace(
@@ -72,7 +72,7 @@ def _patch_transfer_planning(monkeypatch, chain, fileitem, history, planned, del
             get_by_path=lambda path: None,
         ),
     )
-    monkeypatch.setattr("app.chain._mixins.DownloadHistoryOper", lambda: SimpleNamespace(
+    monkeypatch.setattr("app.chain._transfer.DownloadHistoryOper", lambda: SimpleNamespace(
             get_by_hash=lambda download_hash: None,
             get_file_by_fullpath=lambda fullpath: None,
             get_files_by_savepath=lambda savepath: [],
@@ -82,7 +82,7 @@ def _patch_transfer_planning(monkeypatch, chain, fileitem, history, planned, del
         "app.chain.transfer.SystemConfigOper",
         lambda: SimpleNamespace(get=lambda key: None),
     )
-    monkeypatch.setattr("app.chain._mixins.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
+    monkeypatch.setattr("app.chain._transfer.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
     monkeypatch.setattr(
         "app.chain.transfer.StorageChain",
         lambda: SimpleNamespace(
@@ -93,7 +93,7 @@ def _patch_transfer_planning(monkeypatch, chain, fileitem, history, planned, del
             or True,
         ),
     )
-    monkeypatch.setattr("app.chain._mixins.StorageChain", lambda: SimpleNamespace(
+    monkeypatch.setattr("app.chain._transfer.StorageChain", lambda: SimpleNamespace(
             exists=lambda current_fileitem: True,
             delete_media_file=lambda current_fileitem: deleted.append(
                 ("target", current_fileitem.path)

tests/test_music_transfer.py

@@ -68,7 +68,7 @@ def test_music_retry_restores_history_entity_namespace(tmp_path, monkeypatch):
         title="叶惠美",
     )
     monkeypatch.setattr("app.chain.transfer.MediaChain", lambda: media_chain)
-    monkeypatch.setattr("app.chain._mixins.MediaChain", lambda: media_chain)
+    monkeypatch.setattr("app.chain._transfer.MediaChain", lambda: media_chain)
 
     result = TransferChain()._recognize_music_retry_media(
         history,
@@ -538,7 +538,7 @@ def test_success_file_aggregation_is_isolated_between_music_jobs_in_same_directo
         "app.chain.transfer.TransferHistoryOper",
         lambda: SimpleNamespace(),
     )
-    monkeypatch.setattr("app.chain._mixins.TransferHistoryOper", lambda: SimpleNamespace())
+    monkeypatch.setattr("app.chain._transfer.TransferHistoryOper", lambda: SimpleNamespace())
     monkeypatch.setattr(
         "app.chain.transfer.add_transfer_success",
         lambda **kwargs: SimpleNamespace(id=1),
@@ -784,7 +784,7 @@ def test_downloader_process_forwards_music_history_type(tmp_path, monkeypatch):
         ),
     )
     monkeypatch.setattr("app.chain.transfer.MediaChain", lambda: media_chain)
-    monkeypatch.setattr("app.chain._mixins.MediaChain", lambda: media_chain)
+    monkeypatch.setattr("app.chain._transfer.MediaChain", lambda: media_chain)
     monkeypatch.setattr(chain, "do_transfer", Mock(return_value=(True, "")))
     monkeypatch.setattr(chain, "run_module", run_module)
 

tests/test_transfer_custom_words.py

@@ -7,7 +7,7 @@
 """
 from types import SimpleNamespace
 
-import app.chain._mixins as mixins_module
+import app.chain._transfer as mixins_module
 from app.chain.transfer import TransferChain
 
 

tests/test_transfer_failed_retry_buttons.py

@@ -150,7 +150,7 @@ class TestTransferFailedRetryButtons(unittest.TestCase):
                 "app.chain.transfer.TransferHistoryOper"
             ) as history_oper_cls, patch(
                 # mixin 中按自身模块命名空间解析 TransferHistoryOper，需同步镜像
-                "app.chain._mixins.TransferHistoryOper"
+                "app.chain._transfer.TransferHistoryOper"
             ) as mixins_history_oper_cls, patch(
                 "app.chain.transfer.asyncio.run_coroutine_threadsafe",
                 side_effect=_close_pending_coro,
@@ -224,7 +224,7 @@ class TestTransferFailedRetryButtons(unittest.TestCase):
                 "app.chain.transfer.TransferHistoryOper"
             ) as history_oper_cls, patch(
                 # mixin 中按自身模块命名空间解析 TransferHistoryOper，需同步镜像
-                "app.chain._mixins.TransferHistoryOper"
+                "app.chain._transfer.TransferHistoryOper"
             ) as mixins_history_oper_cls, patch(
                 "app.application.agent._agent_manager.run_background_prompt",
                 side_effect=fake_run_background_prompt,

tests/test_transfer_mounted_disk_cleanup.py

@@ -31,7 +31,7 @@ def test_enabled_cleanup_skips_filesystem_detection():
     开关开启时应保持旧行为，且不产生额外文件系统检测。
     """
     with patch(
-            "app.chain._mixins.SystemUtils.is_network_filesystem"
+            "app.chain._transfer.SystemUtils.is_network_filesystem"
     ) as is_network_filesystem:
         should_delete = (
             TransferChain._should_delete_empty_source_directories(
@@ -50,7 +50,7 @@ def test_disabled_cleanup_keeps_mounted_local_source_directories():
     开关关闭时应保留网络或 FUSE 挂载的本地源目录。
     """
     with patch(
-            "app.chain._mixins.SystemUtils.is_network_filesystem",
+            "app.chain._transfer.SystemUtils.is_network_filesystem",
             return_value=True,
     ) as is_network_filesystem:
         should_delete = (
@@ -72,7 +72,7 @@ def test_disabled_cleanup_still_deletes_ordinary_local_source_directories():
     开关关闭时普通本地文件系统仍应删除空目录。
     """
     with patch(
-            "app.chain._mixins.SystemUtils.is_network_filesystem",
+            "app.chain._transfer.SystemUtils.is_network_filesystem",
             return_value=False,
     ):
         should_delete = (
@@ -91,7 +91,7 @@ def test_disabled_cleanup_does_not_change_remote_storage_cleanup():
     开关关闭时非本地存储仍应执行原有空目录清理。
     """
     with patch(
-            "app.chain._mixins.SystemUtils.is_network_filesystem"
+            "app.chain._transfer.SystemUtils.is_network_filesystem"
     ) as is_network_filesystem:
         should_delete = (
             TransferChain._should_delete_empty_source_directories(
@@ -111,7 +111,7 @@ def test_mounted_filesystem_detection_is_cached_by_source_directory():
     """
     mounted_filesystem_cache = {}
     with patch(
-            "app.chain._mixins.SystemUtils.is_network_filesystem",
+            "app.chain._transfer.SystemUtils.is_network_filesystem",
             return_value=True,
     ) as is_network_filesystem:
         for _ in range(2):

tests/test_transfer_movie_collection.py

@@ -107,7 +107,7 @@ def test_conflicting_download_history_recognizes_movie_by_file_meta(monkeypatch)
         "app.chain.transfer.TransferHistoryOper",
         lambda: SimpleNamespace(get_by_type_tmdbid=lambda **kwargs: None),
     )
-    monkeypatch.setattr("app.chain._mixins.TransferHistoryOper", lambda: SimpleNamespace(get_by_type_tmdbid=lambda **kwargs: None))
+    monkeypatch.setattr("app.chain._transfer.TransferHistoryOper", lambda: SimpleNamespace(get_by_type_tmdbid=lambda **kwargs: None))
     monkeypatch.setattr(
         "app.chain.transfer.MediaChain",
         lambda: SimpleNamespace(
@@ -118,7 +118,7 @@ def test_conflicting_download_history_recognizes_movie_by_file_meta(monkeypatch)
             supplement_tmdb_info=lambda media, _meta: media,
         ),
     )
-    monkeypatch.setattr("app.chain._mixins.MediaChain", lambda: SimpleNamespace(
+    monkeypatch.setattr("app.chain._transfer.MediaChain", lambda: SimpleNamespace(
             recognize_media=lambda **kwargs: pytest.fail("不应按合集历史 ID 识别"),
             recognize_by_meta=lambda meta, obtain_images: (
                 recognized_meta.append(meta) or fallback_media
@@ -190,16 +190,16 @@ def test_movie_collection_conflict_only_drops_automatic_media(
         "app.chain.transfer.TransferHistoryOper",
         lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None),
     )
-    monkeypatch.setattr("app.chain._mixins.TransferHistoryOper", lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None))
+    monkeypatch.setattr("app.chain._transfer.TransferHistoryOper", lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None))
     monkeypatch.setattr("app.chain.transfer.DownloadHistoryOper", lambda: history_oper)
-    monkeypatch.setattr("app.chain._mixins.DownloadHistoryOper", lambda: history_oper)
+    monkeypatch.setattr("app.chain._transfer.DownloadHistoryOper", lambda: history_oper)
     monkeypatch.setattr(
         "app.chain.transfer.SystemConfigOper",
         lambda: SimpleNamespace(get=lambda key: None),
     )
-    monkeypatch.setattr("app.chain._mixins.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
+    monkeypatch.setattr("app.chain._transfer.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
     monkeypatch.setattr("app.chain.transfer.StorageChain", lambda: SimpleNamespace())
-    monkeypatch.setattr("app.chain._mixins.StorageChain", lambda: SimpleNamespace())
+    monkeypatch.setattr("app.chain._transfer.StorageChain", lambda: SimpleNamespace())
     monkeypatch.setattr("app.chain.transfer.MetaInfoPath", lambda *args, **kwargs: file_meta)
 
     # 用真 MediaInfo 而非 SimpleNamespace：它会被装进 TransferTask.mediainfo，

tests/test_transfer_sync_extra_files.py

@@ -142,7 +142,7 @@ def test_sync_extra_subtitle_inherits_matching_video_episode(monkeypatch):
         "app.chain.transfer.TransferHistoryOper",
         lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None),
     )
-    monkeypatch.setattr("app.chain._mixins.TransferHistoryOper", lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None))
+    monkeypatch.setattr("app.chain._transfer.TransferHistoryOper", lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None))
     monkeypatch.setattr(
         "app.chain.transfer.DownloadHistoryOper",
         lambda: SimpleNamespace(
@@ -152,7 +152,7 @@ def test_sync_extra_subtitle_inherits_matching_video_episode(monkeypatch):
             get_by_path=lambda path: None,
         ),
     )
-    monkeypatch.setattr("app.chain._mixins.DownloadHistoryOper", lambda: SimpleNamespace(
+    monkeypatch.setattr("app.chain._transfer.DownloadHistoryOper", lambda: SimpleNamespace(
             get_by_hash=lambda download_hash: None,
             get_file_by_fullpath=lambda fullpath: None,
             get_files_by_savepath=lambda savepath: [],
@@ -162,7 +162,7 @@ def test_sync_extra_subtitle_inherits_matching_video_episode(monkeypatch):
         "app.chain.transfer.SystemConfigOper",
         lambda: SimpleNamespace(get=lambda key: None),
     )
-    monkeypatch.setattr("app.chain._mixins.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
+    monkeypatch.setattr("app.chain._transfer.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
     monkeypatch.setattr("app.chain.transfer.MetaInfoPath", fake_meta_info_path)
 
     state, errmsg = TransferChain.do_transfer(
@@ -239,7 +239,7 @@ def test_single_subtitle_transfer_reuses_same_name_video_episode(monkeypatch):
         "app.chain.transfer.TransferHistoryOper",
         lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None),
     )
-    monkeypatch.setattr("app.chain._mixins.TransferHistoryOper", lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None))
+    monkeypatch.setattr("app.chain._transfer.TransferHistoryOper", lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None))
     monkeypatch.setattr(
         "app.chain.transfer.DownloadHistoryOper",
         lambda: SimpleNamespace(
@@ -249,7 +249,7 @@ def test_single_subtitle_transfer_reuses_same_name_video_episode(monkeypatch):
             get_by_path=lambda path: None,
         ),
     )
-    monkeypatch.setattr("app.chain._mixins.DownloadHistoryOper", lambda: SimpleNamespace(
+    monkeypatch.setattr("app.chain._transfer.DownloadHistoryOper", lambda: SimpleNamespace(
             get_by_hash=lambda download_hash: None,
             get_file_by_fullpath=lambda fullpath: None,
             get_files_by_savepath=lambda savepath: [],
@@ -259,7 +259,7 @@ def test_single_subtitle_transfer_reuses_same_name_video_episode(monkeypatch):
         "app.chain.transfer.SystemConfigOper",
         lambda: SimpleNamespace(get=lambda key: None),
     )
-    monkeypatch.setattr("app.chain._mixins.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
+    monkeypatch.setattr("app.chain._transfer.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
     monkeypatch.setattr(
         "app.chain.transfer.StorageChain",
         lambda: SimpleNamespace(
@@ -270,7 +270,7 @@ def test_single_subtitle_transfer_reuses_same_name_video_episode(monkeypatch):
             ],
         ),
     )
-    monkeypatch.setattr("app.chain._mixins.StorageChain", lambda: SimpleNamespace(
+    monkeypatch.setattr("app.chain._transfer.StorageChain", lambda: SimpleNamespace(
             get_parent_item=lambda fileitem: parent_fileitem,
             list_files=lambda fileitem, recursion=False: [
                 main_fileitem,
@@ -354,7 +354,7 @@ def test_single_video_transfer_lists_parent_once_for_same_name_extra(monkeypatch
         "app.chain.transfer.TransferHistoryOper",
         lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None),
     )
-    monkeypatch.setattr("app.chain._mixins.TransferHistoryOper", lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None))
+    monkeypatch.setattr("app.chain._transfer.TransferHistoryOper", lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None))
     monkeypatch.setattr(
         "app.chain.transfer.DownloadHistoryOper",
         lambda: SimpleNamespace(
@@ -364,7 +364,7 @@ def test_single_video_transfer_lists_parent_once_for_same_name_extra(monkeypatch
             get_by_path=lambda path: None,
         ),
     )
-    monkeypatch.setattr("app.chain._mixins.DownloadHistoryOper", lambda: SimpleNamespace(
+    monkeypatch.setattr("app.chain._transfer.DownloadHistoryOper", lambda: SimpleNamespace(
             get_by_hash=lambda download_hash: None,
             get_file_by_fullpath=lambda fullpath: None,
             get_files_by_savepath=lambda savepath: [],
@@ -374,7 +374,7 @@ def test_single_video_transfer_lists_parent_once_for_same_name_extra(monkeypatch
         "app.chain.transfer.SystemConfigOper",
         lambda: SimpleNamespace(get=lambda key: None),
     )
-    monkeypatch.setattr("app.chain._mixins.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
+    monkeypatch.setattr("app.chain._transfer.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
     monkeypatch.setattr(
         "app.chain.transfer.StorageChain",
         lambda: SimpleNamespace(
@@ -382,7 +382,7 @@ def test_single_video_transfer_lists_parent_once_for_same_name_extra(monkeypatch
             list_files=fake_list_files,
         ),
     )
-    monkeypatch.setattr("app.chain._mixins.StorageChain", lambda: SimpleNamespace(
+    monkeypatch.setattr("app.chain._transfer.StorageChain", lambda: SimpleNamespace(
             get_parent_item=lambda fileitem: parent_fileitem,
             list_files=fake_list_files,
         ))
@@ -452,7 +452,7 @@ def test_episode_format_filters_extra_files_before_sync_planning(monkeypatch):
         "app.chain.transfer.TransferHistoryOper",
         lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None),
     )
-    monkeypatch.setattr("app.chain._mixins.TransferHistoryOper", lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None))
+    monkeypatch.setattr("app.chain._transfer.TransferHistoryOper", lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None))
     monkeypatch.setattr(
         "app.chain.transfer.DownloadHistoryOper",
         lambda: SimpleNamespace(
@@ -462,7 +462,7 @@ def test_episode_format_filters_extra_files_before_sync_planning(monkeypatch):
             get_by_path=lambda path: None,
         ),
     )
-    monkeypatch.setattr("app.chain._mixins.DownloadHistoryOper", lambda: SimpleNamespace(
+    monkeypatch.setattr("app.chain._transfer.DownloadHistoryOper", lambda: SimpleNamespace(
             get_by_hash=lambda download_hash: None,
             get_file_by_fullpath=lambda fullpath: None,
             get_files_by_savepath=lambda savepath: [],
@@ -472,7 +472,7 @@ def test_episode_format_filters_extra_files_before_sync_planning(monkeypatch):
         "app.chain.transfer.SystemConfigOper",
         lambda: SimpleNamespace(get=lambda key: None),
     )
-    monkeypatch.setattr("app.chain._mixins.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
+    monkeypatch.setattr("app.chain._transfer.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
     monkeypatch.setattr("app.chain.transfer.MetaInfoPath", lambda path, custom_words=None, **kwargs: FakeMeta(1))
 
     state, errmsg = TransferChain.do_transfer(
@@ -539,7 +539,7 @@ def test_episode_format_keeps_matching_extra_files_following_main(monkeypatch):
         "app.chain.transfer.TransferHistoryOper",
         lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None),
     )
-    monkeypatch.setattr("app.chain._mixins.TransferHistoryOper", lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None))
+    monkeypatch.setattr("app.chain._transfer.TransferHistoryOper", lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None))
     monkeypatch.setattr(
         "app.chain.transfer.DownloadHistoryOper",
         lambda: SimpleNamespace(
@@ -549,7 +549,7 @@ def test_episode_format_keeps_matching_extra_files_following_main(monkeypatch):
             get_by_path=lambda path: None,
         ),
     )
-    monkeypatch.setattr("app.chain._mixins.DownloadHistoryOper", lambda: SimpleNamespace(
+    monkeypatch.setattr("app.chain._transfer.DownloadHistoryOper", lambda: SimpleNamespace(
             get_by_hash=lambda download_hash: None,
             get_file_by_fullpath=lambda fullpath: None,
             get_files_by_savepath=lambda savepath: [],
@@ -559,7 +559,7 @@ def test_episode_format_keeps_matching_extra_files_following_main(monkeypatch):
         "app.chain.transfer.SystemConfigOper",
         lambda: SimpleNamespace(get=lambda key: None),
     )
-    monkeypatch.setattr("app.chain._mixins.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
+    monkeypatch.setattr("app.chain._transfer.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
     monkeypatch.setattr("app.chain.transfer.MetaInfoPath", lambda path, custom_words=None, **kwargs: FakeMeta(1))
 
     state, errmsg = TransferChain.do_transfer(
@@ -635,7 +635,7 @@ def test_single_matching_subtitle_uses_unmatched_video_only_as_context(monkeypat
         "app.chain.transfer.TransferHistoryOper",
         lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None),
     )
-    monkeypatch.setattr("app.chain._mixins.TransferHistoryOper", lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None))
+    monkeypatch.setattr("app.chain._transfer.TransferHistoryOper", lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None))
     monkeypatch.setattr(
         "app.chain.transfer.DownloadHistoryOper",
         lambda: SimpleNamespace(
@@ -645,7 +645,7 @@ def test_single_matching_subtitle_uses_unmatched_video_only_as_context(monkeypat
             get_by_path=lambda path: None,
         ),
     )
-    monkeypatch.setattr("app.chain._mixins.DownloadHistoryOper", lambda: SimpleNamespace(
+    monkeypatch.setattr("app.chain._transfer.DownloadHistoryOper", lambda: SimpleNamespace(
             get_by_hash=lambda download_hash: None,
             get_file_by_fullpath=lambda fullpath: None,
             get_files_by_savepath=lambda savepath: [],
@@ -655,7 +655,7 @@ def test_single_matching_subtitle_uses_unmatched_video_only_as_context(monkeypat
         "app.chain.transfer.SystemConfigOper",
         lambda: SimpleNamespace(get=lambda key: None),
     )
-    monkeypatch.setattr("app.chain._mixins.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
+    monkeypatch.setattr("app.chain._transfer.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
     monkeypatch.setattr(
         "app.chain.transfer.StorageChain",
         lambda: SimpleNamespace(
@@ -666,7 +666,7 @@ def test_single_matching_subtitle_uses_unmatched_video_only_as_context(monkeypat
             ],
         ),
     )
-    monkeypatch.setattr("app.chain._mixins.StorageChain", lambda: SimpleNamespace(
+    monkeypatch.setattr("app.chain._transfer.StorageChain", lambda: SimpleNamespace(
             get_parent_item=lambda fileitem: parent_fileitem,
             list_files=lambda fileitem, recursion=False: [
                 main_fileitem,
@@ -731,7 +731,7 @@ def test_cleanup_dest_fileitem_is_deleted_only_after_allowed_items_exist(monkeyp
         "app.chain.transfer.TransferHistoryOper",
         lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None),
     )
-    monkeypatch.setattr("app.chain._mixins.TransferHistoryOper", lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None))
+    monkeypatch.setattr("app.chain._transfer.TransferHistoryOper", lambda: SimpleNamespace(get_by_src=lambda src, storage=None: None))
     monkeypatch.setattr(
         "app.chain.transfer.DownloadHistoryOper",
         lambda: SimpleNamespace(
@@ -741,7 +741,7 @@ def test_cleanup_dest_fileitem_is_deleted_only_after_allowed_items_exist(monkeyp
             get_by_path=lambda path: None,
         ),
     )
-    monkeypatch.setattr("app.chain._mixins.DownloadHistoryOper", lambda: SimpleNamespace(
+    monkeypatch.setattr("app.chain._transfer.DownloadHistoryOper", lambda: SimpleNamespace(
             get_by_hash=lambda download_hash: None,
             get_file_by_fullpath=lambda fullpath: None,
             get_files_by_savepath=lambda savepath: [],
@@ -751,14 +751,14 @@ def test_cleanup_dest_fileitem_is_deleted_only_after_allowed_items_exist(monkeyp
         "app.chain.transfer.SystemConfigOper",
         lambda: SimpleNamespace(get=lambda key: None),
     )
-    monkeypatch.setattr("app.chain._mixins.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
+    monkeypatch.setattr("app.chain._transfer.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
     monkeypatch.setattr(
         "app.chain.transfer.StorageChain",
         lambda: SimpleNamespace(
             delete_media_file=lambda fileitem: delete_calls.append(fileitem.path) or True,
         ),
     )
-    monkeypatch.setattr("app.chain._mixins.StorageChain", lambda: SimpleNamespace(
+    monkeypatch.setattr("app.chain._transfer.StorageChain", lambda: SimpleNamespace(
             delete_media_file=lambda fileitem: delete_calls.append(fileitem.path) or True,
         ))
     monkeypatch.setattr("app.chain.transfer.MetaInfoPath", lambda path, custom_words=None, **kwargs: FakeMeta(1))
@@ -799,14 +799,14 @@ def test_cleanup_dest_fileitem_is_kept_when_episode_format_matches_nothing(monke
         "app.chain.transfer.SystemConfigOper",
         lambda: SimpleNamespace(get=lambda key: None),
     )
-    monkeypatch.setattr("app.chain._mixins.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
+    monkeypatch.setattr("app.chain._transfer.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
     monkeypatch.setattr(
         "app.chain.transfer.StorageChain",
         lambda: SimpleNamespace(
             delete_media_file=lambda fileitem: delete_calls.append(fileitem.path) or True,
         ),
     )
-    monkeypatch.setattr("app.chain._mixins.StorageChain", lambda: SimpleNamespace(
+    monkeypatch.setattr("app.chain._transfer.StorageChain", lambda: SimpleNamespace(
             delete_media_file=lambda fileitem: delete_calls.append(fileitem.path) or True,
         ))
 
@@ -841,7 +841,7 @@ def test_episode_format_matched_but_filtered_by_size_returns_failure(monkeypatch
         "app.chain.transfer.SystemConfigOper",
         lambda: SimpleNamespace(get=lambda key: None),
     )
-    monkeypatch.setattr("app.chain._mixins.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
+    monkeypatch.setattr("app.chain._transfer.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
 
     state, errmsg = TransferChain.do_transfer(
         chain,
@@ -882,7 +882,7 @@ def test_candidate_collection_checks_continue_callback(monkeypatch):
         "app.chain.transfer.SystemConfigOper",
         lambda: SimpleNamespace(get=lambda key: None),
     )
-    monkeypatch.setattr("app.chain._mixins.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
+    monkeypatch.setattr("app.chain._transfer.SystemConfigOper", lambda: SimpleNamespace(get=lambda key: None))
 
     state, errmsg = TransferChain.do_transfer(
         chain,

tests/test_transfer_tmdb_category.py

@@ -79,14 +79,14 @@ def test_transfer_stops_when_automatic_category_has_no_tmdb_result(monkeypatch)
         "app.chain.transfer.TransferHistoryOper",
         lambda: SimpleNamespace(),
     )
-    monkeypatch.setattr("app.chain._mixins.TransferHistoryOper", lambda: SimpleNamespace())
+    monkeypatch.setattr("app.chain._transfer.TransferHistoryOper", lambda: SimpleNamespace())
     monkeypatch.setattr(
         "app.chain.transfer.MediaChain",
         lambda: SimpleNamespace(
             supplement_tmdb_info=lambda media, _meta: media,
         ),
     )
-    monkeypatch.setattr("app.chain._mixins.MediaChain", lambda: SimpleNamespace(
+    monkeypatch.setattr("app.chain._transfer.MediaChain", lambda: SimpleNamespace(
             supplement_tmdb_info=lambda media, _meta: media,
         ))
     task = TransferTask(