Rewind then Read same file incorrectly shows "Unchanged since last read"

Steps to reproduce:

1. Use Read tool to read any file (e.g., src/index.ts)
2. Rewind the conversation to a point before the Read occurred
3. Use Read tool again on the same file

Expected behavior:
The file content should be read and displayed normally, since the rewind removed it from the context window.

Actual behavior:
Claude Code responds with "Unchanged since last read" and refuses to read the file again, even though the file content is no longer in context.

Workaround:
Use cat via Bash to read the file instead of the Read tool.

Impact:
Breaks the Read tool after rewind, forcing fallback to shell commands for basic file reading.