refactor: move workflow package to dify_graph (#32844)

api/dify_graph/file/protocols.py

@@ -0,0 +1,43 @@
+from __future__ import annotations
+
+from collections.abc import Generator
+from typing import Protocol
+
+
+class HttpResponseProtocol(Protocol):
+    """Subset of response behavior needed by workflow file helpers."""
+
+    @property
+    def content(self) -> bytes: ...
+
+    def raise_for_status(self) -> object: ...
+
+
+class WorkflowFileRuntimeProtocol(Protocol):
+    """Runtime dependencies required by ``dify_graph.file``.
+
+    Implementations are expected to be provided by integration layers (for example,
+    ``core.app.workflow.file_runtime``) so the workflow package avoids importing
+    application infrastructure modules directly.
+    """
+
+    @property
+    def files_url(self) -> str: ...
+
+    @property
+    def internal_files_url(self) -> str | None: ...
+
+    @property
+    def secret_key(self) -> str: ...
+
+    @property
+    def files_access_timeout(self) -> int: ...
+
+    @property
+    def multimodal_send_format(self) -> str: ...
+
+    def http_get(self, url: str, *, follow_redirects: bool = True) -> HttpResponseProtocol: ...
+
+    def storage_load(self, path: str, *, stream: bool = False) -> bytes | Generator: ...
+
+    def sign_tool_file(self, *, tool_file_id: str, extension: str, for_external: bool = True) -> str: ...