C:/Program Files/Git/rename does not persist session name — --resume <name> never finds it

Description

/rename <name> appears to succeed visually during a session, but the name is never persisted. When trying to resume with claude --resume <name>, the session is not found.

Steps to reproduce

1. Start a session: claude
2. Rename it: /rename mcp
3. Exit: /exit
4. Try to resume: claude --resume mcp
5. Result: session not found, opens picker with no match

Investigation

• sessions-index.json has no name field on any entry — only sessionId, summary, firstPrompt, gitBranch, etc.
• The .jsonl session file itself has no sessionName or customName field either
• Confirmed across multiple sessions where /rename was used — none have persisted names
• grep -c '"name"' sessions-index.json → 0
• grep -c 'sessionName\|customName' sessions-index.json → 0

Expected behavior

/rename <name> should persist the name in sessions-index.json (or equivalent), and claude --resume <name> should find and resume that session.

Environment

• Claude Code version: 2.1.42
• OS: Windows 11 Pro (10.0.26200)
• Shell: Git Bash