Fix: Preventing the google,facebook login crash when env files are missing

[AA1-34-Ganesh]

📌 Linked Issue

Closes #78

🛠 Changes Made

• Fixed: Modified handleGoogleLogin and handleFacebookLogin in Login.jsx to prevent execution if API keys are missing.
• Added: Implemented a defensive check to verify if REACT_APP_GOOGLE_CLIENT_ID or REACT_APP_FACEBOOK_APP_ID are undefined or set to default placeholders.
• Updated: The UI now displays a user-friendly error message ("Login not configured in this environment") instead of redirecting users to a broken Google/Facebook 401 error page.

🧪 Testing

• Tested manually:
  • Test case 1: Verified that the application runs locally without crashing on startup.
  • Test case 2: Simulating a Production environment (missing .env keys): Clicked "Sign in with Google". Verified that the app stays on the login page and shows the red error alert instead of redirecting.
  • Test case 3: Verified the same behavior for the Facebook login button.

📸 UI Changes (if applicable)

Feature	Before (Crash / Error)	After (Safe Error Message)
Google Login
Facebook Login

📝 Documentation Updates

• Updated README/docs
• Added code comments

✅ Checklist

• Created a new branch for PR
• Have starred the repository
• Follows JavaScript Styleguide
• No console warnings/errors
• Commit messages follow Git Guidelines

💡 Additional Notes

This fix ensures the application remains stable and professional in production environments (like Netlify/Vercel) even if the maintainer has not yet configured the OAuth secrets. It prevents the "Invalid Client" crash that was reported in Issue #78.

[netlify]

✅ Deploy Preview for smartrentsystem ready!

Built without sensitive environment variables

Name	Link
🔨 Latest commit	e29ab50
🔍 Latest deploy log	https://app.netlify.com/projects/smartrentsystem/deploys/695e3fba5bd2570008b3f496
😎 Deploy Preview	https://deploy-preview-85--smartrentsystem.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.