[BUG] /resume finds no conversations while startup "Recent activity" shows them _ project key mismatch

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

The /resume command reports "No conversations found to resume" even though the startup "Recent activity" screen correctly shows previous conversations for the same project directory.

/resume searches only under the new project key directory, missing all sessions stored under the old key. The global history.jsonl still correctly references them.

What Should Happen?

/resume should find conversations for the current project directory regardless of changes to the internal project key encoding, or should migrate/index old sessions when the encoding changes.

Error Messages/Logs

Steps to Reproduce

1. Run Claude Code in a container with sessions stored under one project key encoding
2. Change something that alters the project key derivation (possibly container config, user context, or a version update)
3. Start a new session in the same project directory
4. Observe that "Recent activity" at startup shows previous conversations
5. Run /resume _ it reports no conversations found

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.70 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

nvironment

• Claude Code version: 2.1.70
• Running inside a container (Linux, root user, $HOME=/home/agent)
• Working directory: /repos/repo---name---temp
• Platform: Linux aarch64