Remote Control: let the agent request activation (user confirms on phone) instead of requiring a manual /remote-control

Feature request

Today /remote-control is a user-only slash command: the agent cannot trigger or even request it. That makes sense as a default — a local session is private to the machine, and the agent should not be able to widen its own exposure surface silently.

However the security argument is weaker than it looks: sessions created from the Claude mobile app / claude.ai/code are reachable from the phone with no QR scan at all. So the friction only exists for locally-started sessions — precisely the ones used for long autonomous runs where remote steering matters most.

Ask: allow the agent to request Remote Control activation, with explicit user confirmation completing the pairing — e.g.:

• agent calls a RequestRemoteControl tool → a confirmation prompt appears in the IDE/terminal and a push notification goes to the already-signed-in Claude mobile app → one tap approves and the session appears in the app;
• or a user setting (remoteControl.autoStart: true) that starts RC automatically for every session in a trusted workspace.

Use case: "I'm leaving for 3 hours, keep working autonomously and let me steer from my phone." The handoff prompt for a fresh session can describe everything except the one step that still requires typing /remote-control manually before walking away.

Related: #83303 (banner). Extension: Claude Code for VS Code, macOS.