Initial commit: ElysiaJS backend + TanStack Start frontend + Traefik compose

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/Dockerfile

@@ -0,0 +1,19 @@
+# --- Frontend: TanStack Start (SSR, Node runtime) ---
+FROM node:22-alpine AS build
+WORKDIR /app
+# VITE_API_URL must be present at build time: Vite inlines it into the bundle.
+ARG VITE_API_URL
+ENV VITE_API_URL=${VITE_API_URL}
+COPY package.json package-lock.json* ./
+RUN npm ci || npm install
+COPY . .
+RUN npm run build
+
+FROM node:22-alpine AS runtime
+WORKDIR /app
+ENV NODE_ENV=production
+ENV PORT=3000
+# TanStack Start (Vite) emits a self-contained server bundle in .output.
+COPY --from=build /app/.output ./.output
+EXPOSE 3000
+CMD ["node", ".output/server/index.mjs"]