Remote Control: model switch from mobile composer does not propagate to host session

Description

When accessing a Claude Code session via Remote Control (iOS app connected to a session spawned on a Mac), switching the model using the model picker in the phone's composer does not actually change the model serving the session. The UI accepts the switch, but subsequent responses are still generated by the original model.

Environment

• Claude Code version: 2.1.246
• Host: macOS (Darwin 25.4.0, arm64, Mac mini)
• Access: Claude Remote Control from iPhone (session spawned on the Mac in spawn mode)

Steps to reproduce

1. Spawn a Claude Code session on a Mac and connect to it from the iPhone app via Remote Control.
2. Session starts on model A (here: Fable 5).
3. In the phone composer, use the model picker to switch to model B (here: Sonnet 5).
4. Send a message asking the model to identify itself, or inspect the session transcript.

Expected

Subsequent requests are served by model B.

Actual

Responses continue to be served by model A. Verified two ways:

• The assistant self-reports as the original model.
• The session's transcript (~/.claude/projects/<slug>/<session-id>.jsonl) records "model":"claude-fable-5" on every assistant message, including all messages sent after the switch.

Notes

• /bug is not available in the remote-control environment, hence filing here.
• Workaround: run /model in the host session directly.