Add "reference open files to context" or "add open files to context" command for the agent panel

[matiaslapolla]

As we have the plus icon to do some actions which include manually selecting files, I want to suggest the addition of a command that allows us to add the opened files to the context.

Cursor has this as a feature and it's one of those that meant a "before & after" for me and also for some other devs I know, that even some didn't realize they needed it until it was there.

Example flow for feature:

• User task is to add a new field to the entity crud flows and make A, B & C changes to existing fields/columns and finally make B required.
• User opens api route file, entity controller, entity service, entity repository, frontend form component and hook/utils, frontend and backend types, and dictionary files.
• User goes to the agent panel and writes "/add-open-files-to-context" and the opened files get automatically added to the context.
• User builds/writes the correct prompt and can trigger the command (this or any other command) by simply adding a "/" without it being between "" or '' neither ``.