Fix Docker build with PostgreSQL dependencies

Dockerfile

@@ -5,9 +5,11 @@ ENV PYTHONDONTWRITEBYTECODE=1 \
     PYTHONUNBUFFERED=1 \
     PYTHONIOENCODING=utf-8
 
-# Install system dependencies
+# Install system dependencies including PostgreSQL client libraries
 RUN apt-get update && apt-get install -y \
     curl \
+    libpq-dev \
+    gcc \
     && rm -rf /var/lib/apt/lists/*
 
 # Create app user and directory