Todo title and description have no character limit

[niat-web]

Bug Report

What happened:
User can type unlimited characters in
the todo title and description fields.
This can break the UI layout with very long text.

Expected behavior:

• Title field: maximum 100 characters
• Description field: maximum 500 characters
• Show character counter below each field
  Example: "45/100 characters"
• Show warning in orange when 80% limit reached
• Show error in red when limit exceeded
• Disable submit button when limit exceeded

Steps to reproduce:

1. Login to the app
2. Click Add New Todo
3. Type very long text in title field
4. Notice no limit is enforced