/resume doesn't surface conversations by custom title from /rename

Description

When using /rename to give a conversation a custom title, the /resume picker does not display or search by that custom title. Renamed conversations become effectively invisible in the resume list unless you know the session UUID.

Steps to Reproduce

1. Start a conversation (especially one initiated from plan mode)
2. Use /rename Flash Talisman to give it a custom title
3. /exit the conversation
4. Use /resume and search for "Flash Talisman"
5. The conversation does not appear

Investigation

Looking at the storage, everything is properly saved:

• The JSONL conversation file contains a "type":"custom-title" entry:

``json
{"type":"custom-title","customTitle":"Flash Talisman and others tweaks","sessionId":"a113da4f-..."}
``

• The session ID exists in ~/.claude/history.jsonl with entries

However, the history.jsonl entries for this session only contain raw display text from user inputs:

{"display":"/rename Flash Talisman and others tweaks","pastedContents":{},"timestamp":...,"sessionId":"a113da4f-..."}
{"display":"/exit","pastedContents":{},"timestamp":...,"sessionId":"a113da4f-..."}

The custom title is stored only inside the per-session JSONL file (~/.claude/projects/<project>/<uuid>.jsonl), not in history.jsonl. The /resume picker appears to only read from history.jsonl and uses the first display field as the conversation label — so it never sees the custom title.

This is especially problematic for conversations started from plan mode, where the first real user message may not be logged to history.jsonl at all, making the first visible entry the /rename slash command itself.

Expected Behavior

• /resume should display conversations using their custom title (from /rename) when one exists
• Custom titles should be searchable/filterable in the /resume picker
• Ideally, history.jsonl should include a customTitle field for sessions that have been renamed, or /resume should read the custom-title entry from the session JSONL files

Environment

• Claude Code v2.1.38
• macOS (Darwin 23.6.0)