feat: initial scaffold with Event Management, Participant Management, and Budget Management

- Express backend with JWT auth, PostgreSQL, full CRUD APIs
- React + Vite + TailwindCSS frontend with RTL Hebrew UI
- Event Creation & Management (create/edit/delete/list events)
- Participant Management (add/edit/delete/status tracking per event)
- Budget Management (income/expense tracking with balance summary)
- Docker Compose setup with PostgreSQL
- /health endpoint with commit-id and DB status

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

Dockerfile

@@ -0,0 +1,24 @@
+FROM node:20-alpine
+
+WORKDIR /app
+
+# Install backend dependencies
+COPY package.json ./
+RUN npm install
+
+# Build frontend
+COPY client/package.json client/
+RUN cd client && npm install
+
+COPY client/ client/
+RUN cd client && npm run build
+
+# Copy server
+COPY server.js ./
+
+EXPOSE 3000
+
+ENV NODE_ENV=production
+ENV PORT=3000
+
+CMD ["node", "server.js"]