Copy Notification Text to Clipboard

### Feature Description

Often, I would like to be able to copy (part of) the notification text (or title) to the clipboard.
Ideally by using keyboard shortcuts or ipc commands.

### Use Case

Receiving a passcode or similar in a notification and need to enter it in a web form.

### Compositor(s)

All compositors

### If Other, please specify

_No response_

### Proposed Solution

I'd love to do a proof-of-concept if someone could give me a pointer into the code on where to start ;-)

### Alternatives/Existing Solutions

_No response_

The issue names no files or tests; start by locating the notification UI and existing clipboard or IPC entry points in the repository. Done means an agreed keyboard-shortcut or IPC path can copy notification text or its title across all listed compositors, covering the passcode use case.

Written by the indexing model from the issue text.