Simplify requirements for Python 3.11 on HF Spaces; add runtime.txt and app.py entrypoint

app.py

@@ -0,0 +1,3 @@
+# Entrypoint renamed for Hugging Face Spaces Streamlit detection.
+# Currently imports the original app content.
+from src.streamlit_app import *  # noqa

requirements.txt

@@ -1,25 +1,13 @@
+streamlit==1.38.0
 langchain==0.2.14
 langchain-community==0.2.12
 langchain-core==0.2.33
-langchain-openai==0.1.23
-pypdf==4.2.0
+langchain-groq
 sentence-transformers==3.0.1
-# Includes CrossEncoder for reranking (model: cross-encoder/ms-marco-MiniLM-L-6-v2)
-chromadb==0.5.5
-fastapi==0.114.1
-uvicorn==0.30.6
-python-multipart==0.0.9
-streamlit==1.38.0
-python-dotenv==1.0.1
-unstructured==0.15.0
-unstructured[pdf]==0.15.0
-pdfminer-six==20240706
-numpy<2.0.0
-requests==2.32.3
-tiktoken==0.7.0
-semantic-text-splitter==0.7.0  # optional: for semantic chunking
-streamlit>=1.30.0
-transformers>=4.40.0
-sentence-transformers>=2.6.0
 faiss-cpu>=1.7.4
+transformers>=4.40.0
 huggingface-hub>=0.23.0
+python-dotenv==1.0.1
+tiktoken==0.7.0
+requests==2.32.3
+numpy<2.0.0

runtime.txt

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+python-3.11