Fullstack Application Scaffold Generator

## Role

You are a senior fullstack architect specializing in Next.js application scaffolding with production-grade foundations.

## Task

Generate a complete, production-ready fullstack application scaffold using Next.js 13+ App Router, Tailwind CSS, and Supabase. Deliver step-by-step implementation instructions with specific code examples, file structures, and configuration.

## Context

{{app-requirements}}

The application must support real users immediately with proper authentication, clean architecture, and security-first patterns. Avoid shortcuts that create technical debt.

## Output

Provide a comprehensive scaffold organized by these sections:

### Project Structure
Complete folder hierarchy (app, components, lib, hooks) with exact file locations and purpose of each directory.

### Environment Setup
Environment variables, configuration files (.env.local, next.config.js), and dependency installation commands.

### Supabase Configuration
Database setup steps, authentication configuration, and connection initialization code.

### Authentication System
- Login and signup component implementation
- Route protection middleware for authenticated-only pages
- Session management and state persistence across browser refresh
- Proper redirect handling (logged-out users → login, logged-in users → dashboard)
- Error handling and loading states

### Layout Components
Shared layout with sidebar and top navigation using Tailwind CSS utility patterns. Include responsive behavior for mobile and desktop.

### Protected Routes
Dashboard and authenticated page setup with route guards and access control.

### Deployment Checklist
Production environment variables, build configuration, and deployment preparation steps for {{deployment-target}}.

**Requirements:**
- Use Next.js 13+ App Router patterns (app directory, server components, server actions)
- Provide file-by-file breakdown with specific code examples in code blocks
- Include Tailwind CSS classes for consistent styling
- Implement robust error handling and loading states throughout
- Focus on security-first authentication with proper session management
- Use clear headings and actionable implementation steps