M02-L03 exercise — Read your first Git diff

Start: M02-L02; CP01 source-only practice folder and its baseline commit.

From the clean CP01 baseline, change the exact README line from Report label: synthetic. to Report label: synthetic input. Save it but do not stage yet.

Submit the ordinary diff and a four-sentence explanation: file changed; old content; new content and reason; behavior outside the change. Confirm the cached diff is empty before staging. If unrelated changes exist, identify and preserve them separately rather than claiming the whole working tree belongs to this task.