fix: Remove hardcoded API keys security vulnerability

[piyushkumar0707]

🔒 Security Fix: Remove Hardcoded API Keys

Problem

The application had hardcoded API keys exposed in utils/chatbot.py:

• GOOGLE_API_KEY was publicly visible in the repository
• CSE_ID was also hardcoded and exposed
• This created a critical security vulnerability

Solution

• ✅ Replaced hardcoded keys with environment variable loading
• ✅ Added proper error handling for missing environment variables
• ✅ Created .gitignore to prevent accidental .env commits
• ✅ Added .env.example template for new contributors
• ✅ Updated README.md with complete setup instructions
• ✅ Added security notice about API key management

Files Changed

• utils/chatbot.py - Fixed security vulnerability
• .gitignore - New file to protect sensitive data
• .env.example - Template for required environment variables
• README.md - Updated with setup instructions and security notice

Testing

• Verified environment variables load correctly
• Confirmed application imports work without errors
• Tested with actual environment file

Impact

• 🛡️ Security: API keys are no longer publicly exposed
• 🚀 Production Ready: Application can now be safely deployed
• 📚 Developer Experience: Clear setup instructions for contributors
• 🔄 Maintainable: Follows security best practices

This fix resolves a critical security vulnerability and makes the project production-ready.