Description:

The current Chrome extension allows the same webpage to be saved multiple times without any warning or notification. This can lead to unnecessary duplicates in the saved content, cluttering the data and making it difficult to manage.

Steps to Reproduce:

1. Install and set up the Chrome extension.
2. Visit a webpage and save it using the extension.
3. Attempt to save the same webpage again by clicking the extension icon.

Expected Behavior:

When a user tries to save a webpage that has already been saved, the extension should:

1. Warn the user that the page has already been saved.
2. Provide an option to either cancel the save or update the existing entry (e.g., adding a new note).

Actual Behavior:

The extension allows the same webpage to be saved multiple times without any notification or check, resulting in duplicate entries.

Proposed Solution:

Implement a duplicate check in the extension that:

1. Identifies if a webpage has already been saved.
2. Prompts the user with a warning if they attempt to save a duplicate.