refacto: reorganize folder tree to split lora gateway stack from app

Those stack won't necessarily be on the same host, so they need to be
split

app/Dockerfile

@@ -1,6 +0,0 @@
-FROM python:3.13-slim
-WORKDIR /app
-COPY requirements.txt .
-RUN pip install --no-cache-dir -r requirements.txt
-COPY main.py .
-CMD ["python", "main.py"]