Initial commit: Pokerface sprint planning poker for Jira

Full-stack app with Express/Socket.io backend, React frontend,
NATS JetStream for state, and Atlassian Jira OAuth integration.

Includes security hardening: NATS auth support, KV bucket TTL
enforcement, CAS retry for race conditions, error message
sanitization, and OAuth state stored in NATS KV.

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

Dockerfile

@@ -0,0 +1,23 @@
+FROM node:22-alpine AS frontend
+
+WORKDIR /app/frontend
+COPY frontend/package.json frontend/package-lock.json ./
+RUN npm ci
+COPY frontend/ ./
+RUN npm run build
+
+FROM node:22-alpine
+
+WORKDIR /app/backend
+COPY backend/package.json backend/package-lock.json ./
+RUN npm ci --omit=dev
+COPY backend/ ./
+
+COPY --from=frontend /app/frontend/dist /app/frontend/dist
+
+ENV NODE_ENV=production
+ENV PORT=4010
+
+EXPOSE 4010
+
+CMD ["node", "src/index.js"]