Add pinned conda environments for arm64 and x86

- envs/environment-docling.yml (arm64, Python 3.12) and envs/environment-local_rag.yml
  (x86_64, Python 3.10) with exact pip versions and create commands in the header
- README and EINSTIEG: how to create the environments; x86 tested for chat, search and
  indexing (search about 2.3 s under Rosetta)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

envs/environment-local_rag.yml

@@ -0,0 +1,114 @@
+# Conda environment "local_rag" (x86_64, Python 3.10.18), exact package versions.
+# Generated 2026-10-26 from the working environment.
+# Alternative for x86_64 (Intel Mac or Rosetta). torch 2.2.2 is the last version for
+# macOS x86; bge-m3 is therefore loaded as safetensors (EMBEDDING_REVISION in local_rag.py).
+# Docling does not run here.
+# Create (on Apple Silicon, force x86 packages):
+#   CONDA_SUBDIR=osx-64 conda env create -f envs/environment-local_rag.yml
+#   conda activate local_rag && conda config --env --set subdir osx-64
+name: local_rag
+channels:
+  - defaults
+dependencies:
+  - python=3.10.18
+  - pip
+  - pip:
+      - aiohappyeyeballs==2.6.1
+      - aiohttp==3.13.3
+      - aiosignal==1.4.0
+      - annotated-doc==0.0.4
+      - annotated-types==0.7.0
+      - anyio==4.12.1
+      - async-timeout==4.0.3
+      - attrs==25.4.0
+      - certifi==2026.1.4
+      - charset-normalizer==3.4.4
+      - click==8.3.1
+      - dataclasses-json==0.6.7
+      - distro==1.9.0
+      - exceptiongroup==1.3.1
+      - faiss-cpu==1.13.2
+      - fastapi==0.128.0
+      - filelock==3.20.3
+      - frozenlist==1.8.0
+      - fsspec==2026.1.0
+      - greenlet==3.3.1
+      - h11==0.16.0
+      - hf-xet==1.2.0
+      - httpcore==1.0.9
+      - httptools==0.7.1
+      - httpx-sse==0.4.3
+      - httpx==0.28.1
+      - huggingface-hub==0.36.0
+      - idna==3.11
+      - Jinja2==3.1.6
+      - jiter==0.13.0
+      - joblib==1.5.3
+      - jsonpatch==1.33
+      - jsonpointer==3.0.0
+      - langchain-classic==1.0.1
+      - langchain-community==0.4.1
+      - langchain-core==1.2.11
+      - langchain-huggingface==1.2.0
+      - langchain-ollama==1.0.1
+      - langchain-openai==1.1.9
+      - langchain-text-splitters==1.1.0
+      - langchain==1.2.7
+      - langgraph-checkpoint==4.0.0
+      - langgraph-prebuilt==1.0.7
+      - langgraph-sdk==0.3.3
+      - langgraph==1.0.7
+      - langsmith==0.6.4
+      - MarkupSafe==3.0.3
+      - marshmallow==3.26.2
+      - mpmath==1.3.0
+      - multidict==6.7.1
+      - mypy_extensions==1.1.0
+      - networkx==3.4.2
+      - numpy==1.26.4
+      - ollama==0.6.1
+      - openai==2.20.0
+      - orjson==3.11.5
+      - ormsgpack==1.12.2
+      - packaging==25.0
+      - propcache==0.4.1
+      - pydantic-settings==2.12.0
+      - pydantic==2.12.5
+      - pydantic_core==2.41.5
+      - pypdf==6.6.2
+      - python-dotenv==1.2.1
+      - PyYAML==6.0.3
+      - rank-bm25==0.2.2
+      - regex==2026.1.15
+      - requests-toolbelt==1.0.0
+      - requests==2.32.5
+      - safetensors==0.7.0
+      - scikit-learn==1.7.2
+      - scipy==1.15.3
+      - sentence-transformers==5.2.1
+      - shellingham==1.5.4
+      - sniffio==1.3.1
+      - snowballstemmer==3.1.1
+      - SQLAlchemy==2.0.46
+      - starlette==0.50.0
+      - sympy==1.14.0
+      - tenacity==9.1.2
+      - threadpoolctl==3.6.0
+      - tiktoken==0.12.0
+      - tokenizers==0.22.2
+      - torch==2.2.2
+      - tqdm==4.67.1
+      - transformers==4.57.6
+      - typer-slim==0.21.1
+      - typing-inspect==0.9.0
+      - typing-inspection==0.4.2
+      - typing_extensions==4.15.0
+      - urllib3==2.6.3
+      - uuid_utils==0.14.0
+      - uvicorn==0.40.0
+      - uvloop==0.22.1
+      - watchfiles==1.1.1
+      - websockets==16.0
+      - xxhash==3.6.0
+      - yarl==1.22.0
+      - zstandard==0.25.0