Full-Stack App Scaffold from Description

I want to build [APP_DESCRIPTION]. Generate a complete project scaffold including:

1. **Tech stack recommendation** — pick the best framework, database, and hosting for this use case. Justify each choice in one sentence.
2. **Directory structure** — output a file tree with every folder and file needed.
3. **Schema design** — database tables/collections with fields, types, and relationships.
4. **API routes** — list every endpoint with method, path, request body, and response shape.
5. **Key components** — list the main UI components with their props and state.
6. **Environment variables** — every env var the project will need.

Use modern best practices (TypeScript, server components where applicable, edge functions). Keep it pragmatic — no over-engineering.