[Feature Request] Add session observation/monitoring mode for improved collaboration

**Bug Description**
This session is just watching another session and helping me convey what I'm trying to do better.

**Environment Info**
- Platform: win32
- Terminal: vscode
- Version: 2.1.273
- Feedback ID: ebf0282e-6459-47a7-b894-1755af8d456a

**Errors**
```json
[]
```

The issue names no files, tests, or entry points and only describes watching another session on win32 through the VS Code terminal. First clarify the monitoring and collaboration behavior, permissions, and expected user experience; completion should be defined by agreed requirements and validation of the resulting session workflow.

Written by the indexing model from the issue text.