fix: correct how Dockerfile copies dirs

backend/Dockerfile

@@ -2,9 +2,14 @@ FROM python:3.11-slim
 
 WORKDIR /app
 
-COPY requirements.txt .
+COPY backend/requirements.txt .
+
 RUN pip install --no-cache-dir -r requirements.txt
 
-COPY . .
+# ✅ Copy the entire backend directory as /app/backend
+COPY backend/ ./backend
 
-CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]
+# ✅ Set PYTHONPATH to include /app
+ENV PYTHONPATH=/app
+
+CMD ["uvicorn", "backend.main:app", "--host", "0.0.0.0", "--port", "8000"]