feat: Merge 2FA functionality from workshop branch to main

[Copilot]

This PR merges the comprehensive Two-Factor Authentication (2FA) system from commit 84220d6d39275ce5427d9732f9ba2a38491e4172 in the workshop branch into the main branch, creating a new branch main-with-2fa with enhanced security features.

🔐 What's Added

The 2FA implementation provides mandatory two-factor authentication for all user registration and login flows using Time-based One-Time Passwords (TOTP).

Backend Changes

• Database Schema: Added verification_hash column to Users table for 2FA validation
• API Extensions: New endpoints for secret verification and 2FA validation
• Configuration: Enhanced config system with 2FA secret management
• Models: Updated User model to support verification hashes

Frontend Changes

• Complete 2FA Library: New 2FA.js with TOTP generation, secret key management, and .secrets file handling
• UI Components: Added TwoFactorDisplay component showing real-time TOTP codes with countdown timer
• Authentication Flow: Completely refactored login/registration to require 2FA validation
• Enhanced Styling: Comprehensive CSS additions for 2FA interface elements

🛠️ Technical Improvements

• ES Module Compatibility: Fixed __dirname issues in Vite configuration for proper ES module support
• Code Quality: Resolved all linting issues including unused imports and variables
• Build System: Ensured all builds pass with the new 2FA dependencies
• SSL Support: Generated development certificates for secure HTTPS operation

🔒 Security Features

• Mandatory 2FA: All authentication now requires valid .secrets file
• TOTP Implementation: Industry-standard 30-second rotating codes
• Secure File Management: Automatic .secrets file download during registration
• Server Validation: Backend verification of 2FA secrets and hashes
• Session Security: Temporary secret storage for active sessions

📋 Files Modified

Backend (6 files):

• BackEnd/BDD/bdd.sql - Database schema update
• BackEnd/config.py - 2FA configuration
• BackEnd/routes/users.py - New verification endpoints
• BackEnd/models.py - User model updates
• BackEnd/Class/api_class_body.py - API body classes
• BackEnd/add_verification_hash.sql - Migration script

Frontend (7 files):

• FrontEnd/src/scripts/2FA.js - Complete 2FA library (new)
• FrontEnd/src/components/auth/TwoFactorDisplay.jsx - TOTP display component (new)
• FrontEnd/src/scripts/Auth.js - Refactored authentication flow
• FrontEnd/src/components/auth/LoginForm.jsx - Updated login flow
• FrontEnd/src/components/auth/RegisterForm.jsx - Updated registration flow
• FrontEnd/src/Styles/Auth.css - 2FA styling additions
• FrontEnd/vite.config.js - ES module compatibility fix

🧪 Quality Assurance

• ✅ All builds pass successfully
• ✅ Linting issues resolved
• ✅ ES module compatibility ensured
• ✅ SSL certificates generated for development
• ✅ Clean commit history maintained

The implementation follows security best practices with client-side TOTP generation and server-side validation, ensuring robust two-factor authentication without compromising user experience.

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