Two more metrics on the same chart, from the portal's new energy_wh and co2e_g
daily columns.
- Energy in watt-hours, carbon in grams CO2e, both for the day shown.
- Continuous metrics use the 1/2/5 axis rule (not the integer rule reserved for
counts), so energy ticks read 500 Wh rather than being rounded to whole
people-style numbers.
- Labels carry units, so a reader never has to guess what the axis measures.
- Same measured-vs-estimated provenance as the data layer: GreenPT models use
facts fitted from their own impact API, everyone else a labelled proxy. The
docs page on estimation is still to be written; the factor table and its
sources are in metrics_snapshot.py.
Harness extended: one bar per measured day for each, no NaN in markup, and axis
labels matching ^[\d,]+(\.\d+)? (Wh|g)$ so a unit prefix or a forced integer
axis fails the build.