Session renamed in the mobile app never reaches the host, so it cannot be found or addressed by that name

What happens

I renamed a session to "the upgrade plan" from the Claude mobile app (the session shows as Connected to my server). On the host machine, that name does not exist anywhere:

• ~/.claude/sessions/*.json lists all 10 live sessions with nameSource: "derived" and placeholder names like thatevilguy-63. None carries the custom name.
• The transcript's aiTitle still reads "Workflow system with credential mocking", the title generated from the opening turn.
• grep -ri 'upgrade plan' ~/.claude/ returns nothing.

I confirmed the session identity by messaging it with SendMessage. It corroborated the topic, and reported that it has no tool or context exposing its own session title, so it cannot state its own name either.

Consequences

1. Finding a session by name fails silently. Asked to find a conversation by the name shown in the app, the agent has no lookup available, so it falls back to listing recent transcripts by modification time and guessing from their content. It then presents that guess confidently, and a wrong answer looks exactly like a right one. This gets worse with scale: I had 10 sessions open and the guess was already unreliable. At 20 there is no practical way to pick the right one without the title.
2. SendMessage cannot address the session by that name. ListAgents only offers the derived placeholder.
3. A session cannot report its own name. Asked directly, it has nothing surfacing its session title or aiTitle.

Why I believe this is a regression

CHANGELOG 2.1.221:

Fixed renaming a session from Claude Code Desktop or claude.ai not updating the CLI's session name; session names from every rename surface are now sanitized

I am on 2.1.234, which is after that fix, and the name still does not reach the host. My guess is the mobile app is not covered as a rename surface.

Expected

A name set on any surface reaches the host session registry, so the session is findable and addressable by that name everywhere. Ideally alongside a lookup that resolves a name to a session id, since aiTitle is already persisted in the transcript and would support exactly that.

Environment

• Claude Code CLI 2.1.234, Linux 6.8.0
• Sessions Connected via Remote Control, renamed from the Claude mobile app
• Read CHANGELOG through 2.1.257: no entry covering this