docs: migrate setup instructions from pip/venv to uv

Replace python -m venv and pip install with uv venv --python 3.12 and
uv pip install. Add uv to CLAUDE.md tooling section and README
requirements list.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -10,9 +10,9 @@ A Hugging Face Spaces app that translates English text to 22 production-ready la
 
 ```bash
 # Setup
-python -m venv .venv
+uv venv --python 3.12
 source .venv/bin/activate
-pip install -r requirements.txt
+uv pip install -r requirements.txt
 
 # Run (launches on http://localhost:7860)
 python app.py
@@ -40,6 +40,7 @@ pytest -m slow             # model tests only (CUDA only)
 
 ## Tooling
 
+- **uv** — Python package manager. Used for venv creation and dependency installation from `requirements.txt`. No `pyproject.toml`; `requirements.txt` remains the single source of truth (required by HF Spaces).
 - **Ruff** — linter and formatter (`ruff.toml`). Rules: `E`, `F`, `I`, `W`. Line length: 120.
 - **ty** — type checker (`ty.toml`). Python 3.12 target.
 - **pytest** — test runner (`pytest.ini`). Custom `slow` marker for CUDA-dependent tests.

README.md

@@ -17,15 +17,16 @@ Translate English text to 22 production-ready languages (BLEU 35+ both direction
 
 ## Requirements
 
+- [uv](https://docs.astral.sh/uv/) (Python package manager)
 - Python 3.12
 - CUDA GPU (recommended) or CPU
 
 ## Setup
 
 ```bash
-python -m venv .venv
+uv venv --python 3.12
 source .venv/bin/activate
-pip install -r requirements.txt
+uv pip install -r requirements.txt
 python app.py
 ```