Add created_at timestamp to Note model and display it in the application details template

[dorkdiaries9]

Description

This pull request adds a created_at timestamp to the Note model and updates the application details template to show when each note was created.

Changes Introduced

• Added created_at (DateTime, default = current timestamp) to the Note model.
• Updated the notes section in the template to display created_at in YYYY-MM-DD HH:MM format.
• Improved note layout for better readability.

Impact

• Displays when each note was added.
• Enhances clarity and user experience.
• Non-breaking change; migration required to apply the new field.

Post-Merge Action

Database migration needs to be executed after merge to apply the new created_at field.

[dorkdiaries9]

@florindonhazua Can you please review.