Initial scaffold: Vite React frontend and Express + Mongo backend

[neeldas0032]

Motivation

• Provide a runnable full-stack starting point for the Morphy fitness demo including both a client SPA and a production-style API server.
• Implement core domain boundaries (auth, diet, progress, AI suggestions, notifications) so features can be iterated independently.
• Add standard infra and DX pieces (request context, structured logging, rate limiting, validation, JWT auth, background jobs) for realistic behavior.

Description

• Add frontend: Vite + React app with UI components, screens, Tailwind config, styles, index.html, src/main.jsx, package.json, and vite.config.js, plus package-lock.json.
• Add backend: Express server under server/ with layered layout (routes, controllers, services, models, middleware, jobs, validators, config, utils), plus startup (server/src/server.js), server/package.json, and server/package-lock.json.
• Implement domain features: authentication (register/login), diet generation and retrieval, progress upsert and weekly fetch, AI suggestions service, notifications creation/listing/mark-read, an hourly cron job to create reminders, and RBAC admin route to list users.
• Add operational helpers and docs: server/.env.example, server/README.md, server/ARCHITECTURE.md, centralized error handling (ApiError, errorMiddleware), request context and logger middleware, rate limiters, validators, JWT utils, and standardized success response envelope.

Testing

• No automated tests were added or executed as part of this change (no test harness included).

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Codex Task