[BUG] Remote Control: worker's custom skills (~/.claude/skills/) missing from Claude app slash-command autocomplete

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When controlling a claude --remote-control worker from the Claude app, the
slash-command autocomplete dropdown only shows built-in commands (/clear,
/model, etc.). The worker's locally-defined custom skills — both user
(~/.claude/skills/) and project (.claude/skills/) — are absent.

Skills are confirmed loaded on the worker: typing the full skill name (e.g.
/work-project) and submitting routes correctly via the Skill tool. Only the
typeahead UI in the controlling app is missing them, forcing the user to
memorize exact names.

The controller session also does not expose /help, so there is no in-app
way to list what skills the worker has loaded. The user must either remember
names or maintain an external list.

The worker's local TUI shows these same skills in autocomplete normally.

Reproduces on both macOS desktop and iOS controller apps against the same
worker.

Related (different transport, same symptom): #57275 covers the cloud-session
variant where the slash menu doesn't appear at all on first turn.

What Should Happen?

When typing / in the controller, the autocomplete dropdown should list all
skills available to the worker session — built-in, user (~/.claude/skills/),
and project (.claude/skills/) — matching what the worker's local TUI shows.
The remote-control protocol should advertise the worker's resolved skill list
to the controller, and /help should be available in the controller session.

Actual: dropdown shows built-in commands only; user/project skills are
absent; /help is not available.

Error Messages/Logs

Steps to Reproduce

1. On an Ubuntu 24.04 worker, with ~/.claude/skills/work-project/SKILL.md

already present (any valid skill).

1. Start claude --remote-control on the worker.
2. From the Claude app (macOS or iOS), connect to the worker session.
3. In the prompt, type /wor.

Expected: dropdown includes /work-project.
Actual: no match. Typing /work-project in full and submitting works.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.150

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

Confirmed: typing the full skill name and submitting routes correctly via
the Skill tool, so worker-side skill resolution is fine. The
remote-control protocol appears not to advertise the worker's resolved
skill list to the controller, and /help is not exposed in the controller
session — so the controller's autocomplete falls back to its built-in
command list only.

Possible fix direction: include the worker's resolved skill manifest
(name, description, argument-hint) in the remote-control handshake or
session-init message, and expose /help in the controller session.