Fix(docker): Run Alembic migrations on container startup

This commit introduces changes to ensure that Alembic database migrations
are automatically applied when the backend Docker container starts.

Key changes:
- Added `be/entrypoint.sh`: This script first runs `alembic upgrade head`
  to apply any pending migrations and then executes the main container
  command (e.g., starting Uvicorn).
- Modified `be/Dockerfile`:
    - The `entrypoint.sh` script is copied into the image and made executable.
    - The Docker `ENTRYPOINT` is set to this script, ensuring migrations
      run before the application starts.
- Updated `docker-compose.yml`:
    - The `DATABASE_URL` for the `backend` service has been set to the
      Neon database URL you provided.
- Verified `be/alembic/env.py`: Confirmed that it correctly sources the
  `DATABASE_URL` from environment variables for Alembic to use.

These changes address the issue where migrations were not being run,
preventing the application from starting correctly.

be/Dockerfile

@@ -49,6 +49,8 @@ COPY --chown=appuser:appuser alembic/ ./alembic/
 COPY --chown=appuser:appuser alembic.ini ./
 COPY --chown=appuser:appuser *.py ./
 COPY --chown=appuser:appuser requirements.txt ./
+COPY --chown=appuser:appuser entrypoint.sh /app/entrypoint.sh
+RUN chmod +x /app/entrypoint.sh
 
 # Create logs directory
 RUN mkdir -p /app/logs && chown -R appuser:appuser /app
@@ -64,6 +66,7 @@ HEALTHCHECK --interval=30s --timeout=10s --start-period=30s --retries=3 \
 EXPOSE 8000
 
 # Production command
+ENTRYPOINT ["/app/entrypoint.sh"]
 CMD ["uvicorn", "app.main:app", \
     "--host", "0.0.0.0", \
     "--port", "8000", \

be/entrypoint.sh

@@ -0,0 +1,10 @@
+#!/bin/sh
+set -e
+
+# Run database migrations
+echo "Running database migrations..."
+alembic upgrade head
+
+# Execute the command passed as arguments to this script
+echo "Starting application..."
+exec "$@"

docker-compose.yml

@@ -33,7 +33,7 @@ services:
       # Pass the database URL to the backend container
       # Uses the service name 'db' as the host, and credentials defined above
       # IMPORTANT: Use the correct async driver prefix if your app needs it!
-      - DATABASE_URL=xxx
+      - DATABASE_URL=postgresql+asyncpg://mitlist_owner:npg_p0SkmyJ6BPWO@ep-small-sound-a9ketcef-pooler.gwc.azure.neon.tech/testnewmig
       - GEMINI_API_KEY=xxx
       - SECRET_KEY=xxx
       # Add other environment variables needed by the backend here