MCP server: tools to read/write environment & folder variables

The MCP server plugin can create, update, and delete requests and folders, but there’s no way to read or set variables. get_environment_id only returns the active environment’s id — not its contents — and there’s no environment CRUD.

Use case

I’ve been driving Yaak from Claude (via the MCP server) to scaffold example requests for an API feature — folders, requests, headers, and path/query params all work great. But it breaks at the last step: the agent writes requests referencing ${[ productId ]}, ${[ notificationId ]}, etc. and then can’t set those values. So every session ends with a manual “now go add these under Folder → Settings → Variables.” Being able to set variables would make agent-assisted setup fully end-to-end.

What I’d like

Environment CRUD tools — create_environment, update_environment, delete_environment (and maybe a set_environment_variable convenience). Since folder-level variables are stored as Environment records (parentModel: “folder” / parentId), one environment surface would cover both workspace and folder-scoped variables.

Feasibility

The write path looks like it could reuse the existing generic upsert_model_request / delete_model_request events — the same mechanism the folder-CRUD PR (#369) used — so it’d be a TypeScript-only change mirroring that PR. A list_environments read/discovery tool would need a small core event, which could be scoped separately.