Workspace trust dialog should identify the remote agent environment and clarify trust scope

## Description

When an agent session opens a folder on a remote environment, the workspace trust dialog only shows the remote filesystem path and does not explain that the folder comes from a remote, or identify which remote it belongs to.

The dialog currently says that trusting the folder will also mark it as trusted in the local Visual Studio Code client. This makes the scope and effect of the decision unclear: it is not obvious what trusting something in the client means when the files and commands belong to an agent running on another remote.

## Expected behavior

The dialog should:

- Clearly indicate that the folder is hosted on a remote agent environment.
- Identify the specific remote/environment involved.
- Explain which trust state is being changed and what effect that trust has locally versus on the remote agent.
- Avoid implying that a local trust decision has broader remote effects unless those effects are explicit.