Advanced paste without AI

### Description of the new feature / enhancement

I want to be able to automatically modify my copied item without using AI credits and instead use basic scripting.

### Scenario when this would be used?

For example, if I copy an x.com link, it replaces it with fixupx.com when I paste it. This is simple regex scripting and shouldn't require AI.

### Supporting information

_No response_

The issue names no files, tests, or entry points, so first identify where Advanced Paste handles copied text and whether scripting is already supported. Done should mean a user can apply basic regex-based transformations such as changing x.com links to fixupx.com without consuming AI credits.

Written by the indexing model from the issue text.