fix: unblock concurrent threads and workspace hydration (#1839)

* fix: unblock concurrent threads and workspace hydration

* fix: restore async title generation

* fix: address PR review feedback

* style: format lead agent prompt

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

@@ -8,6 +8,14 @@ from deerflow.subagents import get_available_subagent_names
 logger = logging.getLogger(__name__)
 
 
+def _get_enabled_skills():
+    try:
+        return list(load_skills(enabled_only=True))
+    except Exception:
+        logger.exception("Failed to load enabled skills for prompt injection")
+        return []
+
+
 def _build_subagent_section(max_concurrent: int) -> str:
     """Build the subagent system prompt section with dynamic concurrency limit.
 
@@ -282,7 +290,7 @@ You: "Deploying to staging..." [proceed]
 **Example - Inline Citations:**
 ```markdown
 The key AI trends for 2026 include enhanced reasoning capabilities and multimodal integration
-[citation:AI Trends 2026](https://techcrunch.com/category/artificial-intelligence/).
+[citation:AI Trends 2026](https://techcrunch.com/ai-trends).
 Recent breakthroughs in language models have also accelerated progress
 [citation:OpenAI Research](https://openai.com/research).
 ```
@@ -294,7 +302,7 @@ Recent breakthroughs in language models have also accelerated progress
 DeerFlow is an open-source AI agent framework that gained significant traction in early 2026
 [citation:GitHub Repository](https://github.com/bytedance/deer-flow). The project focuses on
 providing a production-ready agent system with sandbox execution and memory management
-[citation:DeerFlow Documentation](https://github.com/bytedance/deer-flow?tab=readme-ov-file#table-of-contents).
+[citation:DeerFlow Documentation](https://deer-flow.dev/docs).
 
 ## Key Analysis
 
@@ -307,10 +315,10 @@ combined with a FastAPI gateway for REST API access [citation:FastAPI](https://f
 
 ### Primary Sources
 - [GitHub Repository](https://github.com/bytedance/deer-flow) - Official source code and documentation
-- [DeerFlow Documentation](https://github.com/bytedance/deer-flow?tab=readme-ov-file#table-of-contents) - Technical specifications
+- [DeerFlow Documentation](https://deer-flow.dev/docs) - Technical specifications
 
 ### Media Coverage
-- [AI Trends 2026](https://techcrunch.com/category/artificial-intelligence/) - Industry analysis
+- [AI Trends 2026](https://techcrunch.com/ai-trends) - Industry analysis
 ```
 
 **CRITICAL: Sources section format:**
@@ -386,7 +394,7 @@ def get_skills_prompt_section(available_skills: set[str] | None = None) -> str:
     Returns the <skill_system>...</skill_system> block listing all enabled skills,
     suitable for injection into any agent's system prompt.
     """
-    skills = load_skills(enabled_only=True)
+    skills = _get_enabled_skills()
 
     try:
         from deerflow.config import get_app_config
@@ -450,7 +458,7 @@ def get_deferred_tools_prompt_section() -> str:
 
         if not get_app_config().tool_search.enabled:
             return ""
-    except FileNotFoundError:
+    except Exception:
         return ""
 
     registry = get_deferred_registry()

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

@@ -101,44 +101,33 @@ class TitleMiddleware(AgentMiddleware[TitleMiddlewareState]):
         return user_msg if user_msg else "New Conversation"
 
     def _generate_title_result(self, state: TitleMiddlewareState) -> dict | None:
-        """Synchronously generate a title. Returns state update or None."""
+        """Generate a local fallback title without blocking on an LLM call."""
         if not self._should_generate_title(state):
             return None
 
-        prompt, user_msg = self._build_title_prompt(state)
-        config = get_title_config()
-        model = create_chat_model(name=config.model_name, thinking_enabled=False)
-
-        try:
-            response = model.invoke(prompt)
-            title = self._parse_title(response.content)
-            if not title:
-                title = self._fallback_title(user_msg)
-        except Exception:
-            logger.exception("Failed to generate title (sync)")
-            title = self._fallback_title(user_msg)
-
-        return {"title": title}
+        _, user_msg = self._build_title_prompt(state)
+        return {"title": self._fallback_title(user_msg)}
 
     async def _agenerate_title_result(self, state: TitleMiddlewareState) -> dict | None:
-        """Asynchronously generate a title. Returns state update or None."""
+        """Generate a title asynchronously and fall back locally on failure."""
         if not self._should_generate_title(state):
             return None
 
-        prompt, user_msg = self._build_title_prompt(state)
         config = get_title_config()
-        model = create_chat_model(name=config.model_name, thinking_enabled=False)
+        prompt, user_msg = self._build_title_prompt(state)
 
         try:
+            if config.model_name:
+                model = create_chat_model(name=config.model_name, thinking_enabled=False)
+            else:
+                model = create_chat_model(thinking_enabled=False)
             response = await model.ainvoke(prompt)
             title = self._parse_title(response.content)
-            if not title:
-                title = self._fallback_title(user_msg)
+            if title:
+                return {"title": title}
         except Exception:
-            logger.exception("Failed to generate title (async)")
-            title = self._fallback_title(user_msg)
-
-        return {"title": title}
+            logger.debug("Failed to generate async title; falling back to local title", exc_info=True)
+        return {"title": self._fallback_title(user_msg)}
 
     @override
     def after_model(self, state: TitleMiddlewareState, runtime: Runtime) -> dict | None: