Add an Output panel right-click behavior to copy selected text like the terminal

## Feature request

In the integrated terminal, VS Code can be configured so that right-click copies the current selection to the clipboard. It would be useful to have the same option for the Output panel.

## Current behavior

When text is selected in the Output panel and the user right-clicks, VS Code opens the context menu. Copying requires choosing `Copy` from that menu or using `Ctrl+C`.

## Desired behavior

Provide a setting for the Output panel that lets right-click copy the selected text directly to the clipboard, similar to the terminal right-click copy behavior.

For example, this could be exposed as an Output-panel equivalent of `terminal.integrated.rightClickBehavior`, with an option such as `copySelection`.

## Why this would help

The Output panel is often used to inspect logs and command output. Copying small fragments from logs is a frequent workflow, and matching the terminal behavior would make the interaction faster and more consistent across VS Code output surfaces.

## Screenshot / context

The current Output panel context menu already contains `Copy`, but right-click always opens the menu instead of copying the selected text directly.