refactor(workflow-file): phase1 migrate workflow file deps with compatibility bridge

Implement phase 1 of the file module migration by moving workflow-facing file primitives to core.workflow.file while keeping core.file as a temporary compatibility layer.

What this commit changes
- Add core.workflow.file package (constants/enums/models/helpers/file_manager/tool_file_parser).
- Add protocol-based runtime binding in core.workflow.file.runtime and core.workflow.file.protocols.
- Add application adapter core.app.workflow.file_runtime and bind runtime in extensions.ext_storage.init_app.
- Bind runtime in tests via tests/conftest.py.
- Migrate workflow-only imports from core.file.* to core.workflow.file.* across workflow runtime/nodes/entry/encoder and workflow node factory.
- Update workflow unit tests to patch/import the new workflow file namespace.
- Remove workflow-external-imports ignore_imports entries related to core.file from .importlinter.

Compatibility guarantee for phase split
- Keep core.file import path available in this phase by replacing core/file/*.py with forwarding bridge modules that re-export core.workflow.file symbols.
- Preserve runtime behavior and isinstance(File) identity consistency while non-workflow modules are still on legacy import paths.

Notes
- This commit intentionally does not remove core.file. Full repository replacement and bridge removal are handled in phase 2.

api/tests/conftest.py

@@ -0,0 +1,8 @@
+import pytest
+
+from core.app.workflow.file_runtime import bind_dify_workflow_file_runtime
+
+
+@pytest.fixture(autouse=True)
+def _bind_workflow_file_runtime() -> None:
+    bind_dify_workflow_file_runtime()

api/tests/unit_tests/core/workflow/nodes/llm/test_file_saver.py

@@ -6,10 +6,10 @@ import httpx
 import pytest
 from sqlalchemy import Engine
 
-from core.file import FileTransferMethod, FileType, models
 from core.helper import ssrf_proxy
 from core.tools import signature
 from core.tools.tool_file_manager import ToolFileManager
+from core.workflow.file import FileTransferMethod, FileType, models
 from core.workflow.nodes.llm.file_saver import (
     FileSaverImpl,
     _extract_content_type_and_extension,

api/tests/unit_tests/core/workflow/nodes/llm/test_node.py

@@ -8,7 +8,6 @@ import pytest
 from core.app.entities.app_invoke_entities import InvokeFrom, ModelConfigWithCredentialsEntity
 from core.entities.provider_configuration import ProviderConfiguration, ProviderModelBundle
 from core.entities.provider_entities import CustomConfiguration, SystemConfiguration
-from core.file import File, FileTransferMethod, FileType
 from core.model_runtime.entities.common_entities import I18nObject
 from core.model_runtime.entities.message_entities import (
     ImagePromptMessageContent,
@@ -21,6 +20,7 @@ from core.model_runtime.entities.model_entities import AIModelEntity, FetchFrom,
 from core.model_runtime.model_providers.model_provider_factory import ModelProviderFactory
 from core.variables import ArrayAnySegment, ArrayFileSegment, NoneSegment
 from core.workflow.entities import GraphInitParams
+from core.workflow.file import File, FileTransferMethod, FileType
 from core.workflow.nodes.llm import llm_utils
 from core.workflow.nodes.llm.entities import (
     ContextConfig,

api/tests/unit_tests/core/workflow/nodes/llm/test_scenarios.py

@@ -2,9 +2,9 @@ from collections.abc import Mapping, Sequence
 
 from pydantic import BaseModel, Field
 
-from core.file import File
 from core.model_runtime.entities.message_entities import PromptMessage
 from core.model_runtime.entities.model_entities import ModelFeature
+from core.workflow.file import File
 from core.workflow.nodes.llm.entities import LLMNodeChatModelMessage
 
 

api/tests/unit_tests/core/workflow/nodes/test_document_extractor_node.py

@@ -6,12 +6,12 @@ import pytest
 from docx.oxml.text.paragraph import CT_P
 
 from core.app.entities.app_invoke_entities import InvokeFrom
-from core.file import File, FileTransferMethod
 from core.variables import ArrayFileSegment
 from core.variables.segments import ArrayStringSegment
 from core.variables.variables import StringVariable
 from core.workflow.entities import GraphInitParams
 from core.workflow.enums import NodeType, WorkflowNodeExecutionStatus
+from core.workflow.file import File, FileTransferMethod
 from core.workflow.node_events import NodeRunResult
 from core.workflow.nodes.document_extractor import DocumentExtractorNode, DocumentExtractorNodeData
 from core.workflow.nodes.document_extractor.node import (
@@ -146,7 +146,7 @@ def test_run_extract_text(
     mock_ssrf_proxy_get.return_value.content = file_content
     mock_ssrf_proxy_get.return_value.raise_for_status = Mock()
 
-    monkeypatch.setattr("core.file.file_manager.download", mock_download)
+    monkeypatch.setattr("core.workflow.file.file_manager.download", mock_download)
     monkeypatch.setattr("core.helper.ssrf_proxy.get", mock_ssrf_proxy_get)
 
     if mime_type == "application/pdf":

api/tests/unit_tests/core/workflow/nodes/test_if_else.py

@@ -6,10 +6,10 @@ import pytest
 
 from core.app.entities.app_invoke_entities import InvokeFrom
 from core.app.workflow.node_factory import DifyNodeFactory
-from core.file import File, FileTransferMethod, FileType
 from core.variables import ArrayFileSegment
 from core.workflow.entities import GraphInitParams
 from core.workflow.enums import WorkflowNodeExecutionStatus
+from core.workflow.file import File, FileTransferMethod, FileType
 from core.workflow.graph import Graph
 from core.workflow.nodes.if_else.entities import IfElseNodeData
 from core.workflow.nodes.if_else.if_else_node import IfElseNode

api/tests/unit_tests/core/workflow/nodes/test_list_operator.py

@@ -3,9 +3,9 @@ from unittest.mock import MagicMock
 import pytest
 
 from core.app.entities.app_invoke_entities import InvokeFrom
-from core.file import File, FileTransferMethod, FileType
 from core.variables import ArrayFileSegment
 from core.workflow.enums import WorkflowNodeExecutionStatus
+from core.workflow.file import File, FileTransferMethod, FileType
 from core.workflow.nodes.list_operator.entities import (
     ExtractConfig,
     FilterBy,

api/tests/unit_tests/core/workflow/nodes/tool/test_tool_node.py

@@ -8,12 +8,12 @@ from unittest.mock import MagicMock, patch
 
 import pytest
 
-from core.file import File, FileTransferMethod, FileType
 from core.model_runtime.entities.llm_entities import LLMUsage
 from core.tools.entities.tool_entities import ToolInvokeMessage
 from core.tools.utils.message_transformer import ToolFileMessageTransformer
 from core.variables.segments import ArrayFileSegment
 from core.workflow.entities import GraphInitParams
+from core.workflow.file import File, FileTransferMethod, FileType
 from core.workflow.node_events import StreamChunkEvent, StreamCompletedEvent
 from core.workflow.runtime import GraphRuntimeState, VariablePool
 from core.workflow.system_variable import SystemVariable

api/tests/unit_tests/core/workflow/nodes/webhook/test_webhook_node.py

@@ -3,10 +3,10 @@ from unittest.mock import patch
 import pytest
 
 from core.app.entities.app_invoke_entities import InvokeFrom
-from core.file import File, FileTransferMethod, FileType
 from core.variables import FileVariable, StringVariable
 from core.workflow.entities.graph_init_params import GraphInitParams
 from core.workflow.entities.workflow_node_execution import WorkflowNodeExecutionStatus
+from core.workflow.file import File, FileTransferMethod, FileType
 from core.workflow.nodes.trigger_webhook.entities import (
     ContentType,
     Method,

api/tests/unit_tests/core/workflow/test_system_variable.py

@@ -4,8 +4,8 @@ from typing import Any
 import pytest
 from pydantic import ValidationError
 
-from core.file.enums import FileTransferMethod, FileType
-from core.file.models import File
+from core.workflow.file.enums import FileTransferMethod, FileType
+from core.workflow.file.models import File
 from core.workflow.system_variable import SystemVariable
 
 # Test data constants for SystemVariable serialization tests

api/tests/unit_tests/core/workflow/test_system_variable_read_only_view.py

@@ -2,7 +2,7 @@ from typing import cast
 
 import pytest
 
-from core.file.models import File, FileTransferMethod, FileType
+from core.workflow.file.models import File, FileTransferMethod, FileType
 from core.workflow.system_variable import SystemVariable, SystemVariableReadOnlyView
 
 

api/tests/unit_tests/core/workflow/test_variable_pool.py

@@ -3,7 +3,6 @@ from collections import defaultdict
 
 import pytest
 
-from core.file import File, FileTransferMethod, FileType
 from core.variables import FileSegment, StringSegment
 from core.variables.segments import (
     ArrayAnySegment,
@@ -27,6 +26,7 @@ from core.variables.variables import (
     Variable,
 )
 from core.workflow.constants import CONVERSATION_VARIABLE_NODE_ID, ENVIRONMENT_VARIABLE_NODE_ID, SYSTEM_VARIABLE_NODE_ID
+from core.workflow.file import File, FileTransferMethod, FileType
 from core.workflow.runtime import VariablePool
 from core.workflow.system_variable import SystemVariable
 from factories.variable_factory import build_segment, segment_to_variable

api/tests/unit_tests/core/workflow/test_workflow_entry.py

@@ -3,14 +3,14 @@ from types import SimpleNamespace
 import pytest
 
 from configs import dify_config
-from core.file.enums import FileType
-from core.file.models import File, FileTransferMethod
 from core.helper.code_executor.code_executor import CodeLanguage
 from core.variables.variables import StringVariable
 from core.workflow.constants import (
     CONVERSATION_VARIABLE_NODE_ID,
     ENVIRONMENT_VARIABLE_NODE_ID,
 )
+from core.workflow.file.enums import FileType
+from core.workflow.file.models import File, FileTransferMethod
 from core.workflow.nodes.code.code_node import CodeNode
 from core.workflow.nodes.code.limits import CodeNodeLimits
 from core.workflow.runtime import VariablePool