feat: initial brainstorming app — Nuxt 3 + SQLite + admin auth

Nuxt 3 app with:
- SQLite (better-sqlite3) for persistence
- Anonymous idea submission and voting
- Admin auth with session cookies
- AI analysis via Gemini API
- Nuxt UI components + Tailwind

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Dockerfile

@@ -0,0 +1,19 @@
+FROM node:24-alpine AS build
+RUN apk add --no-cache python3 make g++
+WORKDIR /app
+RUN corepack enable pnpm
+COPY package.json pnpm-lock.yaml ./
+RUN pnpm install --frozen-lockfile
+COPY . .
+RUN pnpm run build
+
+FROM node:24-alpine AS run
+ENV NODE_ENV=production
+WORKDIR /app
+RUN mkdir -p /data && chown node:node /data
+COPY --from=build /app/.output ./.output
+USER node
+EXPOSE 3000
+HEALTHCHECK --interval=30s --timeout=5s --retries=3 --start-period=15s \
+  CMD wget -q --spider http://localhost:3000/api/health || exit 1
+ENTRYPOINT ["node", ".output/server/index.mjs"]