fix: resolve import migrations and test failures after segment 3 merge

- Migrate core.model_runtime -> dify_graph.model_runtime across 20+ files
- Migrate core.workflow.file -> dify_graph.file across 15+ files
- Migrate core.workflow.enums -> dify_graph.enums in service files
- Fix SandboxContext phantom import in dify_graph/context/__init__.py
- Fix core.app.workflow.node_factory -> core.workflow.node_factory
- Fix toast import paths (useToastContext from toast/context)
- Fix app-info.tsx import paths for relocated app-operations
- Fix 15 frontend test files for API changes, missing QueryClientProvider,
  i18n key renames, and component behavior changes

Made-with: Cursor

api/tests/unit_tests/core/agent/patterns/test_base.py

@@ -4,7 +4,7 @@ from decimal import Decimal
 from unittest.mock import MagicMock
 
 import pytest
-from core.model_runtime.entities.llm_entities import LLMUsage
+from dify_graph.model_runtime.entities.llm_entities import LLMUsage
 
 from core.agent.entities import AgentLog, ExecutionContext
 from core.agent.patterns.base import AgentPattern

api/tests/unit_tests/core/agent/patterns/test_function_call.py

@@ -4,8 +4,8 @@ from decimal import Decimal
 from unittest.mock import MagicMock
 
 import pytest
-from core.model_runtime.entities.llm_entities import LLMUsage
-from core.model_runtime.entities.message_entities import (
+from dify_graph.model_runtime.entities.llm_entities import LLMUsage
+from dify_graph.model_runtime.entities.message_entities import (
     PromptMessageTool,
     SystemPromptMessage,
     UserPromptMessage,
@@ -312,7 +312,7 @@ class TestPromptMessageHandling:
 
     def test_assistant_message_with_tool_calls(self, mock_model_instance, mock_context, mock_tool):
         """Test that assistant messages can contain tool calls."""
-        from core.model_runtime.entities.message_entities import AssistantPromptMessage
+        from dify_graph.model_runtime.entities.message_entities import AssistantPromptMessage
 
         tool_call = AssistantPromptMessage.ToolCall(
             id="call_123",

api/tests/unit_tests/core/agent/patterns/test_react.py

@@ -6,7 +6,7 @@ import pytest
 
 from core.agent.entities import ExecutionContext
 from core.agent.patterns.react import ReActStrategy
-from core.model_runtime.entities import SystemPromptMessage, UserPromptMessage
+from dify_graph.model_runtime.entities import SystemPromptMessage, UserPromptMessage
 
 
 @pytest.fixture
@@ -33,7 +33,7 @@ def mock_context():
 @pytest.fixture
 def mock_tool():
     """Create a mock tool."""
-    from core.model_runtime.entities.message_entities import PromptMessageTool
+    from dify_graph.model_runtime.entities.message_entities import PromptMessageTool
 
     tool = MagicMock()
     tool.entity.identity.name = "test_tool"
@@ -158,7 +158,7 @@ class TestBuildPromptWithReactFormat:
     def test_scratchpad_appended_as_assistant_message(self, mock_model_instance, mock_context):
         """Test that agent scratchpad is appended as AssistantPromptMessage."""
         from core.agent.entities import AgentScratchpadUnit
-        from core.model_runtime.entities import AssistantPromptMessage
+        from dify_graph.model_runtime.entities import AssistantPromptMessage
 
         strategy = ReActStrategy(
             model_instance=mock_model_instance,

api/tests/unit_tests/core/agent/patterns/test_strategy_factory.py

@@ -3,7 +3,7 @@
 from unittest.mock import MagicMock
 
 import pytest
-from core.model_runtime.entities.model_entities import ModelFeature
+from dify_graph.model_runtime.entities.model_entities import ModelFeature
 
 from core.agent.entities import AgentEntity, ExecutionContext
 from core.agent.patterns.function_call import FunctionCallStrategy

api/tests/unit_tests/core/agent/test_agent_app_runner.py

@@ -4,10 +4,10 @@ from decimal import Decimal
 from unittest.mock import MagicMock, patch
 
 import pytest
-from core.model_runtime.entities.llm_entities import LLMUsage
+from dify_graph.model_runtime.entities.llm_entities import LLMUsage
 
 from core.agent.entities import AgentEntity, AgentLog, AgentPromptEntity, AgentResult
-from core.model_runtime.entities import SystemPromptMessage, UserPromptMessage
+from dify_graph.model_runtime.entities import SystemPromptMessage, UserPromptMessage
 
 
 class TestOrganizePromptMessages:
@@ -184,7 +184,7 @@ class TestClearUserPromptImageMessages:
 
     def test_original_messages_not_modified(self, mock_runner):
         """Test that original messages are not modified (deep copy)."""
-        from core.model_runtime.entities.message_entities import (
+        from dify_graph.model_runtime.entities.message_entities import (
             ImagePromptMessageContent,
             TextPromptMessageContent,
         )
@@ -365,13 +365,13 @@ class TestOrganizeUserQuery:
 
     def test_query_with_files(self, mock_runner):
         """Test organizing a query with files."""
-        from core.workflow.file.models import File
+        from dify_graph.file.models import File
 
         mock_file = MagicMock(spec=File)
         mock_runner.files = [mock_file]
 
         with patch("core.agent.agent_app_runner.file_manager") as mock_fm:
-            from core.model_runtime.entities.message_entities import ImagePromptMessageContent
+            from dify_graph.model_runtime.entities.message_entities import ImagePromptMessageContent
 
             mock_fm.to_prompt_message_content.return_value = ImagePromptMessageContent(
                 data="http://example.com/image.jpg",