Resume session picker does not display custom session names set via /rename

Description

When using /rename to give a session a custom name, the name is not displayed in the claude --resume session picker. Instead, the picker always shows the first user message (or last command) as the session label.

This makes /rename almost useless for session management — you can't find sessions by the names you gave them.

Steps to Reproduce

1. Start a new Claude Code session
2. Run /rename my-descriptive-name
3. Run /exit
4. Run claude --resume
5. Observe that the session is listed by the first user message, not "my-descriptive-name"

Expected Behavior

The resume session picker should display the custom session name (set via /rename) as the primary label. If no custom name is set, fall back to displaying the first user message.

Actual Behavior

The picker always shows the first user message or last command, completely ignoring the custom name.

Additional Context

• The picker bottom bar shows Ctrl+R to rename, but this is a catch-22: you can't rename a session you can't identify, and you can't identify it because the name isn't shown.
• The search box also doesn't seem to match against custom session names, so even typing the name you set doesn't help find the session.

Screenshots

Resume picker showing first messages instead of custom names:

The current session was renamed to "questions-to-claude" via /rename, but the picker shows "/rename" (the last command) as the label instead.

Environment

• Claude Code CLI (latest)
• Linux (Fedora 42)