fix(api): make alembic migrations idempotent for fresh databases

- 001: guard has_table check; skip if session_data already TEXT
- 002: guard each ADD COLUMN / CREATE TABLE; guard password migration
- 003: guard has_table; guard nullable check
- 004: guard has_table; skip if users.id already TEXT
- env.py: add Base.metadata.create_all after run_migrations to bootstrap fresh DBs
- api/user.py: make hashed_password nullable; add email_verified, image, email_inbound_token fields

Co-Authored-By: Paperclip <noreply@paperclip.ing>

Dockerfile

@@ -12,6 +12,8 @@ RUN pip install --no-cache-dir --prefix=/install .
 
 FROM python:3.12-slim AS prod
 
+RUN apt-get update && apt-get install -y --no-install-recommends libpq5 && rm -rf /var/lib/apt/lists/*
+
 WORKDIR /app
 RUN adduser --system --group --uid 1000 app
 COPY --from=build /install /usr/local
@@ -25,4 +27,4 @@ EXPOSE 8000
 HEALTHCHECK --interval=30s --timeout=3s \
     CMD python -c "import urllib.request; urllib.request.urlopen('http://localhost:8000/health')"
 
-CMD ["uvicorn", "cartsnitch_api.main:app", "--host", "0.0.0.0", "--port", "8000"]
+CMD ["sh", "-c", "python -m alembic upgrade head && uvicorn cartsnitch_api.main:app --host 0.0.0.0 --port 8000"]