Add Dockerfile, docker-compose.yml, and coolify.json for deployment

SPA pattern: node build → nginx serve on port 3000, exposed via HOST_PORT.
Deploys to box-repoapps as spike-breakdown on port 2011, domain spikes.dotrepo.com.

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

Dockerfile

@@ -0,0 +1,14 @@
+FROM node:22-alpine AS build
+WORKDIR /app
+COPY package.json package-lock.json ./
+RUN npm ci
+COPY . .
+RUN npm run build
+
+FROM nginx:alpine
+RUN sed -i 's/listen\s*80;/listen 3000;/g' /etc/nginx/conf.d/default.conf
+RUN sed -i '/location \/ {/a\        try_files $uri $uri/ /index.html;' /etc/nginx/conf.d/default.conf
+COPY --from=build /app/dist /usr/share/nginx/html
+EXPOSE 3000
+HEALTHCHECK --interval=60s --timeout=10s --retries=3 \
+  CMD wget -qO- http://localhost:3000/ || exit 1