feat: add contacts phase 2, advanced search, vacation responder, Docker & TOTP 2FA

- Contact groups/lists, vCard import/export (RFC 6350), bulk operations
- Advanced search with JMAP filter panel, search chips, cross-mailbox queries
- Vacation responder with JMAP VacationResponse, settings tab, sidebar indicator
- TOTP two-factor authentication support
- Docker multi-stage build with standalone output and docker-compose
- CSP Report-Only headers and security headers via proxy middleware
- Virtual scrolling for large email lists
- Structured server-side logger (text/JSON, configurable level)
- 450+ tests (contacts, vCard, threads, headers, identity, components)
- Playwright E2E framework setup
- Updated README and ROADMAP with all new features

Dockerfile

@@ -0,0 +1,20 @@
+FROM node:24-alpine AS builder
+WORKDIR /app
+COPY package.json package-lock.json ./
+RUN npm ci
+COPY . .
+RUN npx next build --webpack
+
+FROM node:24-alpine AS runner
+WORKDIR /app
+ENV NODE_ENV=production
+RUN addgroup --system --gid 1001 nodejs && \
+    adduser --system --uid 1001 nextjs
+COPY --from=builder /app/public ./public
+COPY --from=builder --chown=nextjs:nodejs /app/.next/standalone ./
+COPY --from=builder --chown=nextjs:nodejs /app/.next/static ./.next/static
+USER nextjs
+EXPOSE 3000
+ENV PORT=3000
+ENV HOSTNAME="0.0.0.0"
+CMD ["node", "server.js"]