[add]: code refractoring and cleanup

Dockerfile

@@ -1,20 +1,23 @@
 FROM python:3.11-slim
 
+# Set the working directory in the container
 WORKDIR /app
 
+# Copy the current directory contents into the container at /app
+COPY . /app
+
 RUN apt-get update && apt-get install -y libpq-dev && rm -rf /var/lib/apt/lists/*
 
 COPY requirements.txt .
 RUN pip install -r requirements.txt
 
-COPY salary_analytics/ ./salary_analytics/
 
 RUN mkdir -p output/csv output/plots output/models
 
-ENV PYTHONPATH=/app
-ENV HOST=0.0.0.0
-ENV PORT=8000
+
+ENV FLASK_APP=wsgi.py
+ENV FLASK_RUN_HOST=0.0.0.0
 
 EXPOSE 8000
 
-CMD ["uvicorn", "salary_analytics.api:app", "--host", "0.0.0.0", "--port", "8000", "--reload"] 
+CMD ["gunicorn", "-w", "4", "-b", "0.0.0.0:8000", "wsgi:wsgi_app"]