Session name set by /rename is overwritten after /resume

Description

When resuming a named session via /resume, the custom session name set by /rename gets overwritten with an auto-generated title based on conversation content.

Steps to Reproduce

1. Start a session
2. Run /rename my-session-name to name the session
3. Exit the session
4. Run /resume or claude --resume my-session-name to resume the session
5. Work in the session, then exit
6. Run /resume again to see the session list

Expected Behavior

The session should retain the custom name my-session-name set by /rename.

Actual Behavior

The custom name is replaced with an auto-generated title based on conversation content. The original name is lost.

Additional Context

• This happens consistently across multiple sessions
• Renaming again with /rename works temporarily, but the name gets overwritten again after the next resume
• Version: 2.1.33
• OS: macOS (Darwin 25.2.0)