System-reminder shows stale file state after conversation rollback

Description

When a user rolls back a conversation (escape twice + rollback), the system-reminder in the next message still shows file modifications from before the rollback, even though the files on disk have been reverted.

Steps to Reproduce

1. Have an agent make changes to a file (e.g., 09-kohierrun.md)
2. Roll back the conversation using escape twice + rollback (which should also revert file changes)
3. Send a new message to Claude
4. The <system-reminder> tag in the new message still contains the diff of the file modifications that were supposedly reverted

Expected Behavior

After conversation rollback (with file revert), the system-reminder should reflect the actual current state of files on disk - i.e., no modifications shown if the files were reverted.

Actual Behavior

The system-reminder shows stale/cached file modification diffs from before the rollback, causing Claude to have knowledge of content that no longer exists in the files.

Impact

• Claude references content that doesn't exist in the codebase
• User confusion when Claude knows about "reverted" changes
• Potential for Claude to make incorrect assumptions based on stale state

Environment

• Claude Code CLI
• Model: claude-opus-4-5-20251101