Fix Docker permission issues for Hugging Face Spaces

- Create non-root user 'app' to avoid permission issues
- Set UV_CACHE_DIR to writable location in app directory
- Change ownership of app directory to non-root user
- Add .uv-cache to .dockerignore for cleaner builds

.dockerignore

@@ -20,6 +20,9 @@ coverage.xml
 .venv
 .venv*/
 
+# UV cache
+.uv-cache
+
 # IDE
 .vscode
 .idea

Dockerfile

@@ -1,5 +1,8 @@
 FROM python:3.12-slim
 
+# Create a non-root user
+RUN useradd --create-home --shell /bin/bash app
+
 # Set working directory
 WORKDIR /app
 
@@ -13,8 +16,15 @@ RUN apt-get update && apt-get install -y \
 # Install uv
 RUN pip install uv
 
-# Copy project files
+# Copy project files and change ownership
 COPY . .
+RUN chown -R app:app /app
+
+# Switch to non-root user
+USER app
+
+# Set uv cache directory to a writable location
+ENV UV_CACHE_DIR=/app/.uv-cache
 
 # Install dependencies using uv
 RUN uv sync --frozen