feat: Implement OAuth Authentication System with JWT

[vreshch]

Overview

This PR implements a comprehensive OAuth authentication system for the Agentage platform with stateless JWT token-based authentication.

Changes

Backend Changes

• OAuth Service: Implemented GitHub, Google, and Microsoft OAuth strategies
• Authentication Routes: Created OAuth endpoints with JWT token generation
• Added protected endpoints: /me, /providers, /status

Frontend Changes

• Authentication Components: LoginButton, LoginModal, UserMenu
• Auth Hooks: useAuth hook for managing authentication state
• Auth API: Client for authentication endpoints
• Callback Page: Handles OAuth redirects

Documentation

• Enhanced auth-setup.md with comprehensive setup instructions
• Added Microsoft OAuth setup guide

Testing

✅ All verification commands passed:

• npm run type-check - Successful
• npm run lint - No errors
• npm run test - Passed
• npm run build - Successful

Features

• Multi-Provider OAuth (GitHub, Google, Microsoft)
• JWT Authentication
• User Management
• Protected Routes
• Frontend Integration
• Token Storage
• Cross-Tab Sync

Security

• JWT tokens expire after 7 days
• Email validation on OAuth
• No password storage
• Type-safe implementation

[github-actions]

✅ Pull Request Validation Successful

Step Results:

• ✅ 📦 Install dependencies: true
• ✅ 🔍 Run linting: true
• ✅ 🧪 Run tests: true
• ✅ 🏗️ Build packages: true

🎉 All quality checks passed! Ready to merge.

📋 View workflow run

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🐳 Docker Images Built Successfully!

🏷️ Tag: pr-8

• Backend: ✅ Built
• Frontend: ✅ Built

📋 View workflow

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⏰ Generated at: 2025-11-21T23:00:38.446Z