[Feature] Improve error messages

[AmanatAliPanhwer]

🌟 Summary

Improve the user-facing error messages to be more informative and user-friendly.

🧩 Problem or Motivation

Currently, error messages can be generic or expose technical details that are not helpful to the end-user. Better error messages will improve the user experience.

🧰 Proposed Solution

• Review all user-facing error messages (e.g., login failed, post not found, form validation).
• Rewrite messages to be clear, concise, and provide actionable advice where possible.
• Implement a consistent design for displaying errors.

📦 Technical Considerations

• Frontend changes (HTML/JS/CSS)
• Backend changes (Flask, Supabase)
• Database changes
• Authentication/Authorization
• UI/UX improvements

🧠 Alternatives

N/A

🧾 Additional Context

This will improve the overall polish and professionalism of the application.