PR Guardian AI - First Release

PR Guardian AI v1.0.0 is the first official release of this GitHub App.
It introduces full AI-powered pull request reviewing, automatic GitHub comments, secure GitHub App authentication, and webhook-based PR event handling.

This version includes:

• AI analysis of code changes using OpenAI
• Automatic review comments on Pull Requests
• Support for PR events (opened, reopened, synchronized)
• Installation event handling
• FastAPI backend for high performance
• Secure JWT authentication and installation access tokens
• Fully documented README + MIT license

This marks the first stable and production-ready version of PR Guardian AI.