tools/progress_history.py measures the first-parent history of main with
the rules of tools/progress.py, one point per day, and writes history.json,
history.svg and history.html. The Progress workflow runs it after
progress.py; the README shows the chart under the map and links the page.
Labels and points compact as days accumulate.
Co-Authored-By: Claude <noreply@anthropic.com>