[Feature] Cursor Cloud Agents

[zhamann]

I'd like to add support for launching and managing Cursor Cloud Agents.

The workflow to add includes choosing a GitHub repo and branch, sending a task to a Cursor-hosted environment, and returning to T3 to follow its progress and continue the conversation.

My proposed scope is:

• An opt-in "Cursor Cloud" provider with an API key stored on the T3 server.
• Launch from an existing GitHub-backed project using an explicitly selected remote ref.
• Show progress and responses, send follow-ups, and cancel the current run.
• Restore tracking after a disconnect or server restart.
• Link to the Cursor agent and its resulting branch or PR.

The main architectural question is how a cloud thread should fit T3's workspace model. I'd propose a separate cursor-cloud driver using the existing provider-instance system, with explicit capabilities so local checkpoint, terminal, and worktree operations don't run against the wrong filesystem. Local-to-cloud session migration, automatic checkout of results, and embedded remote desktop controls would be outside this first version.

Cursor's public API appears to cover the required agent/run lifecycle and streaming.

[juliusmarminge]

Duplicate of #6677 — please continue the conversation there.