docs: Update README with comprehensive Portkey setup and configuration

[aj47]

Summary

This PR updates the README to properly reflect the current codebase structure and provides comprehensive setup instructions for Portkey AI Gateway integration.

Changes Made

README Updates

• ✅ Updated tech stack to reflect current dependencies (Next.js 15, Portkey AI, Supabase Auth)
• ✅ Added detailed Portkey setup instructions with account creation and virtual keys
• ✅ Added Supabase authentication setup instructions
• ✅ Created comprehensive environment variables documentation
• ✅ Added project structure overview
• ✅ Updated deployment instructions for Vercel and other platforms
• ✅ Added tips for best results and usage guidelines

Configuration Improvements

• ✅ Created .env.example file with all required and optional environment variables
• ✅ Made virtual keys configurable via environment variables in route.ts
• ✅ Updated .gitignore to allow .env.example while still ignoring actual env files
• ✅ Added comprehensive inline documentation for environment setup

Code Changes

• ✅ Modified src/app/api/generate/route.ts to use environment variables for virtual keys
• ✅ Added fallback to default virtual keys if custom ones aren't provided
• ✅ Improved code comments explaining the Portkey configuration

Key Features Documented

1. Multi-Provider AI Generation: Portkey gateway with Cerebras, Groq, OpenRouter, and OpenAI fallbacks
2. Framework Support: Multiple CSS frameworks (Tailwind, Bootstrap, Materialize, etc.)
3. Authentication: Supabase Auth integration
4. Environment Configuration: Comprehensive setup with optional overrides

Environment Variables

Variable	Required	Description
PORTKEY_API_KEY	✅ Yes	Portkey API key for AI gateway
NEXT_PUBLIC_SUPABASE_URL	❌ Optional	For authentication features
NEXT_PUBLIC_SUPABASE_ANON_KEY	❌ Optional	For authentication features
PORTKEY_*_VIRTUAL_KEY	❌ Optional	Override default virtual keys

Testing

• ✅ Verified all environment variable references
• ✅ Confirmed virtual key fallback logic works
• ✅ Validated README instructions are complete and accurate

This makes the project much easier to set up for new contributors and properly documents the Portkey integration that powers the AI generation functionality.

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Pull Request opened by Augment Code with guidance from the PR author