fix(docker): COPY README.md into build context (hatchling metadata requires it)

Dockerfile

@@ -18,7 +18,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 WORKDIR /app
 
 # Install Python deps first (cached layer).
-COPY pyproject.toml ./
+COPY pyproject.toml README.md ./
 COPY src/ src/
 RUN pip install --no-cache-dir -e ".[data]"
 

Dockerfile.train

@@ -25,7 +25,7 @@ RUN pip install --no-cache-dir \
     "unsloth[cu121-torch240] @ git+https://github.com/unslothai/unsloth.git"
 
 # 2. Install project + all training deps
-COPY pyproject.toml ./
+COPY pyproject.toml README.md ./
 COPY src/ src/
 RUN pip install --no-cache-dir -e ".[data,training]"