Show active workspace and default team in `auth status`

[dubscode]

Summary

Please include active workspace/user/default team information in linear auth status --json.

Current behavior

linear auth status --json shows useful auth details like profile, method, token presence, scopes, and redirect URI. It does not make the active Linear workspace or default team obvious.

Requested fields

Example shape:

{
  "profile": "default",
  "method": "oauth",
  "user": {
    "id": "...",
    "name": "Daniel Wise",
    "email": "..."
  },
  "workspace": {
    "id": "...",
    "name": "BB Scholar",
    "urlKey": "bb-scholar"
  },
  "defaultTeam": {
    "id": "...",
    "key": "BB",
    "name": "Scholar"
  }
}

Why this matters

When a user has access to multiple Linear workspaces, it is easy to end up querying the wrong one or comparing behavior across tools that are authenticated to different workspaces.

A clear workspace/team summary in auth status would make debugging much faster and would help agents confirm they are operating in the expected Linear context before creating or updating issues.

Expected behavior

• Human output should show the active workspace and user.
• JSON output should include stable IDs plus human-readable names.
• If there is no default team, report that explicitly instead of omitting the field.