fix: improve API error handling with detailed messages

[prisha-sh]

📝 Description

Improves API error handling by displaying clear and user-friendly messages for different failure scenarios such as invalid city, network issues, and general API errors. This enhances user experience and prevents confusion during failed requests.

🔗 Related Issue

Closes #37

🔄 Type of Change

• 🐛 Bug fix
• ✨ New feature
• 🔍 SEO improvement
• 🎨 Style / UI improvement
• ♿ Accessibility improvement
• 📝 Documentation
• ⚙️ CI / configuration
• 🧹 Refactor / cleanup

🧪 How to Test

1. Search for a valid city → data loads normally
2. Search for an invalid city → shows "City not found"
3. Turn off internet → shows "Network error, please try again"
4. Simulate API failure → shows "Something went wrong"
5. UI remains stable and allows retry

📸 Screenshots (if applicable)

N/A

✅ Checklist

• My code follows the project's existing style
• I have tested my changes
• I have linked the related issue above
• My PR title follows Conventional Commits format