Session rename breaks resume by name

Description

/rename changes the session display name but discards the original. When resuming, the session appears under its renamed label with no trace of the original name.

Steps to reproduce

1. Start a new session (auto-named or manually named "elton")
2. Run /rename kiki
3. Exit the session
4. Resume — session displays as "kiki" with no indication it was ever "elton"

Expected behavior

Either:

• --resume by original name still works, or
• The original name is preserved somewhere visible (e.g., "kiki (was: elton)")

Actual behavior

The original session name is lost. No way to find the session by its original name after renaming.

Environment

• Claude Code CLI
• macOS