Rewrite as uv-based Flask web app with Dockerfile

- Flask dashboard with Plotly charts (stores, monthly, hourly, weekday, heatmap)
- Spotify Wrapped-style summary with year dropdown and inflation toggle
- CSV upload flow (ephemeral, no storage)
- Homepage with upload and saved data options
- Import script for loading CSVs into SQLite
- Dockerized with gunicorn for production

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Dockerfile

@@ -0,0 +1,14 @@
+FROM python:3.14-slim
+
+COPY --from=ghcr.io/astral-sh/uv:latest /uv /uvx /bin/
+
+WORKDIR /app
+
+COPY pyproject.toml uv.lock ./
+RUN uv sync --frozen --no-dev
+
+COPY app.py import_csv.py ./
+
+EXPOSE 8000
+
+CMD ["uv", "run", "gunicorn", "app:app", "--bind", "0.0.0.0:8000", "--workers", "2", "--timeout", "120"]