fix: HuggingFace Spaces Dockerfile - port 7860, user 1000

Dockerfile

@@ -1,24 +1,18 @@
 FROM python:3.11-slim
 
-WORKDIR /app
+RUN useradd -m -u 1000 user
+USER user
+ENV PATH="/home/user/.local/bin:$PATH"
 
-# Install build tools + runtime lib in one layer
-RUN apt-get update && apt-get install -y --no-install-recommends \
-        build-essential \
-        libpq-dev \
-    && rm -rf /var/lib/apt/lists/*
+WORKDIR /app
 
-# Install dependencies directly into the image's Python (no prefix tricks)
-COPY requirements.txt .
-RUN pip install --no-cache-dir -r requirements.txt
+COPY --chown=user ./requirements.txt requirements.txt
+RUN pip install --no-cache-dir --upgrade -r requirements.txt
 
-# Copy application source
-COPY . .
+COPY --chown=user . /app
 
 ENV PYTHONDONTWRITEBYTECODE=1 \
     PYTHONUNBUFFERED=1 \
-    PORT=8000
-
-EXPOSE 8000
+    SECRET_KEY=hf-default-secret-change-me-in-settings
 
-CMD ["sh", "-c", "uvicorn main:app --host 0.0.0.0 --port ${PORT:-8000} --workers 1"]
+CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "7860"]