Fix runtime errors: Update imports and dependencies

- Fix langchain_community imports to langchain_openai
- Update requirements.txt with correct dependencies
- Add missing langchain-core and pydantic packages
- Fix import statements in all agent files

agents/citation_formatter.py

@@ -4,7 +4,7 @@ LangChain LLMChain for generating bibliography from research notes and draft.
 from langchain.callbacks.base import BaseCallbackHandler
 from langchain.chains import LLMChain
 from langchain.prompts import PromptTemplate
-from langchain_community.llms import OpenAI
+from langchain_openai import OpenAI
 
 import os
 

agents/draft_writer.py

@@ -5,7 +5,7 @@ from typing import Any, Dict, Generator
 from langchain.callbacks.base import BaseCallbackHandler
 from langchain.chains import LLMChain
 from langchain.prompts import PromptTemplate
-from langchain_community.llms import OpenAI
+from langchain_openai import OpenAI
 
 from streaming_config import get_chunk_size, is_yield_enabled
 import os

agents/outline_builder.py

@@ -4,7 +4,7 @@ LangChain LLMChain for building research paper outlines.
 from langchain.callbacks.base import BaseCallbackHandler
 from langchain.chains import LLMChain
 from langchain.prompts import PromptTemplate
-from langchain_community.llms import OpenAI
+from langchain_openai import OpenAI
 
 import os
 

agents/research_retriever.py

@@ -6,7 +6,7 @@ from typing import Any, Dict, Generator
 from langchain.callbacks.base import BaseCallbackHandler
 from langchain.chains import LLMChain
 from langchain.prompts import PromptTemplate
-from langchain_community.llms import OpenAI
+from langchain_openai import OpenAI
 
 from streaming_config import get_chunk_size, is_yield_enabled
 import os

agents/topic_analyzer.py

@@ -3,7 +3,7 @@ LangChain LLMChain for analyzing and refining a research topic with yield suppor
 """
 from langchain.chains import LLMChain
 from langchain.prompts import PromptTemplate
-from langchain_community.llms import OpenAI
+from langchain_openai import OpenAI
 from langchain.callbacks.base import BaseCallbackHandler
 import os
 from typing import Dict, Any, Generator

requirements.txt

@@ -1,9 +1,12 @@
-gradio>=4.0.0
+gradio>=4.44.0
 langgraph>=0.2.0
 langchain>=0.2.0
+langchain-community>=0.2.0
 langchain-openai>=0.2.0
+langchain-core>=0.2.0
 openai>=1.0.0
 python-dotenv>=1.0.0
 reportlab>=4.0.0
-asyncio
-typing
+asyncio-compat>=0.1.2
+typing-extensions>=4.0.0
+pydantic>=2.0.0