Initial commit: CRDC Arrests API demo app

React + Vite static site demonstrating the CRDC School Arrest Rate API.
Features 6 interactive charts comparing observed arrest data against Bayesian
model estimates across U.S. school districts, with Civilytics visual identity.

- State selector and district search with 'interesting' suggestions (top arrests)
- Animated histogram loading grid showing posterior draw progress
- Charts: time series, rate by group, district vs national, model comparison quadrants, density proxy, exceedance probability
- Static JSON fixture for national rates (no API changes needed)
- Dockerfile + docker-compose.yml for self-hosted deployment
- GitHub Actions workflow and _config.yml for Git Pages

Dockerfile

@@ -0,0 +1,22 @@
+# Multi-stage build for the CRDC Arrests API Demo app.
+# Stage 1: Build static files with Vite + React
+FROM node:22-alpine AS builder
+
+WORKDIR /app
+COPY package*.json ./
+RUN npm ci --prefer-offline
+
+COPY . .
+# The VITE_API_BASE env var can be set at build time to point to a different API endpoint.
+ARG VITE_API_BASE=https://crdc-api.civilytics.org/api/v1
+ENV VITE_API_BASE=${VITE_API_BASE}
+RUN npm run build
+
+# Stage 2: Serve with nginx (tiny image, ~5MB)
+FROM nginx:alpine AS runtime
+COPY --from=builder /app/dist/ /usr/share/nginx/html/
+# Custom nginx config for SPA routing + caching headers
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+
+EXPOSE 80
+CMD ["nginx", "-g", "daemon off;"]