Simulated sed -i File-History E2E Test Plan

Goal

Verify that a simple sed -i shell edit is previewed as a file edit, tracked in file history, and reversible through /rewind.

Manual Flow

1. Create a temporary project with file.txt containing foo foo.
2. Start qwen-code in that project.
3. Ask the agent to run sed -i 's/foo/bar/g' file.txt.
4. Confirm that the permission UI shows a file diff from foo foo to bar bar instead of only a shell command confirmation.
5. Approve the edit.
6. Confirm file.txt contains bar bar.
7. Run /rewind to the turn before the sed edit.
8. Confirm file.txt is restored to foo foo.

Fallback Flow

1. In the same project, ask the agent to run sed -i 's/foo/bar/g' *.txt.
2. Confirm the command uses the normal shell confirmation path, because globbed multi-file edits are intentionally not simulated.
3. Cancel the command.

Expected Result

Simple single-file substitutions are tracked like Edit/WriteFile changes and can be rewound. Unsupported sed forms preserve the previous shell behavior.