feat: enhance chat history loading with new hooks and UI components (#2338)

* Refactor API fetch calls to use a unified fetch function; enhance chat history loading with new hooks and UI components

- Replaced `fetchWithAuth` with a generic `fetch` function across various API modules for consistency.
- Updated `useThreadStream` and `useThreadHistory` hooks to manage chat history loading, including loading states and pagination.
- Introduced `LoadMoreHistoryIndicator` component for better user experience when loading more chat history.
- Enhanced message handling in `MessageList` to accommodate new loading states and history management.
- Added support for run messages in the thread context, improving the overall message handling logic.
- Updated translations for loading indicators in English and Chinese.

* Fix test assertions for run ordering in RunManager tests

- Updated assertions in `test_list_by_thread` to reflect correct ordering of runs.
- Modified `test_list_by_thread_is_stable_when_timestamps_tie` to ensure stable ordering when timestamps are tied.

backend/packages/harness/deerflow/agents/lead_agent/agent.py

@@ -1,7 +1,7 @@
 import logging
 
 from langchain.agents import create_agent
-from langchain.agents.middleware import AgentMiddleware, SummarizationMiddleware
+from langchain.agents.middleware import AgentMiddleware
 from langchain_core.runnables import RunnableConfig
 
 from deerflow.agents.lead_agent.prompt import apply_prompt_template
@@ -9,6 +9,7 @@ from deerflow.agents.middlewares.clarification_middleware import ClarificationMi
 from deerflow.agents.middlewares.loop_detection_middleware import LoopDetectionMiddleware
 from deerflow.agents.middlewares.memory_middleware import MemoryMiddleware
 from deerflow.agents.middlewares.subagent_limit_middleware import SubagentLimitMiddleware
+from deerflow.agents.middlewares.summarization_middleware import SummarizationMiddleware
 from deerflow.agents.middlewares.title_middleware import TitleMiddleware
 from deerflow.agents.middlewares.todo_middleware import TodoMiddleware
 from deerflow.agents.middlewares.token_usage_middleware import TokenUsageMiddleware

backend/packages/harness/deerflow/agents/middlewares/loop_detection_middleware.py

@@ -283,7 +283,7 @@ class LoopDetectionMiddleware(AgentMiddleware[AgentState]):
             # the conversation; injecting one mid-conversation crashes
             # langchain_anthropic's _format_messages(). HumanMessage works
             # with all providers. See #1299.
-            return {"messages": [HumanMessage(content=warning)]}
+            return {"messages": [HumanMessage(content=warning, name="loop_warning")]}
 
         return None
 

backend/packages/harness/deerflow/agents/middlewares/summarization_middleware.py

@@ -0,0 +1,13 @@
+from typing import override
+
+from langchain.agents.middleware import SummarizationMiddleware as BaseSummarizationMiddleware
+from langchain_core.messages.human import HumanMessage
+
+
+class SummarizationMiddleware(BaseSummarizationMiddleware):
+    @override
+    def _build_new_messages(self, summary: str) -> list[HumanMessage]:
+        """Override the base implementation to let the human message with the special name 'summary'.
+        And this message will be ignored to display in the frontend, but still can be used as context for the model.
+        """
+        return [HumanMessage(content=f"Here is a summary of the conversation to date:\n\n{summary}", name="summary")]

backend/packages/harness/deerflow/agents/middlewares/thread_data_middleware.py

@@ -1,8 +1,10 @@
 import logging
+from datetime import UTC, datetime
 from typing import NotRequired, override
 
 from langchain.agents import AgentState
 from langchain.agents.middleware import AgentMiddleware
+from langchain_core.messages import HumanMessage
 from langgraph.config import get_config
 from langgraph.runtime import Runtime
 
@@ -97,8 +99,20 @@ class ThreadDataMiddleware(AgentMiddleware[ThreadDataMiddlewareState]):
             paths = self._create_thread_directories(thread_id, user_id=user_id)
             logger.debug("Created thread data directories for thread %s", thread_id)
 
+        messages = list(state.get("messages", []))
+        last_message = messages[-1] if messages else None
+
+        if last_message and isinstance(last_message, HumanMessage):
+            messages[-1] = HumanMessage(
+                content=last_message.content,
+                id=last_message.id,
+                name=last_message.name or "user-input",
+                additional_kwargs={**last_message.additional_kwargs, "run_id": runtime.context.get("run_id"), "timestamp": datetime.now(UTC).isoformat()},
+            )
+
         return {
             "thread_data": {
                 **paths,
-            }
+            },
+            "messages": messages,
         }

backend/packages/harness/deerflow/agents/middlewares/uploads_middleware.py

@@ -279,6 +279,7 @@ class UploadsMiddleware(AgentMiddleware[UploadsMiddlewareState]):
         updated_message = HumanMessage(
             content=f"{files_message}\n\n{original_content}",
             id=last_message.id,
+            name=last_message.name,
             additional_kwargs=last_message.additional_kwargs,
         )