[Enhancement] CSP Compliance and User Feedback Improvements on Welcome Page

[ShindeNikhil8]

📌 Summary

The current welcome.html includes inline JavaScript, which violates Chrome Extension Content Security Policy (CSP) rules and results in errors like:

In addition, there's no visual feedback for users when:

• API key is being validated
• An error occurs during validation
• Theme preferences are saved

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✅ Proposed Enhancements

1. CSP Compliance

   • Move all inline <script> logic to an external welcome.js file
   • Ensures CSP compatibility for Chrome extension runtime

2. Improved User Feedback

   • Add visible error message when API key is missing or invalid
   • Show a loading indicator or disable button during API key validation
   • Add success message when key is saved

3. Consistent Theme Handling

   • Use chrome.storage.local instead of localStorage to store theme mode (dark/light)
   • Sync behavior with popup.js for a consistent experience

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💡 Benefits

• Resolves CSP violations and ensures proper extension loading
• Improves usability by providing clear feedback
• Makes code cleaner and more maintainable

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📁 Files Affected

• popup/welcome.html
• popup/welcome.js
• popup/popup.js (for storage consistency)

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📎 Related PR

These changes are already implemented and proposed in PR #158

Let me know if you'd like me to update anything!