[zebraengine]

Problem

The heat-rise and temperature charts scaled their y-axis to the data, so they started around 20 C. The power, current and relay charts already started at 0.

Code touched

wallmonitor/static/app.js only:

• scatterChart gains the zeroBase option lineChart already has: the y range is extended down to 0, nothing else changes.
• zeroBase: true on four charts:
  • Alerts page: "Handle heat rise per charging segment"
  • Alerts page: "Heat rise vs ambient" (y axis only; the ambient x axis still fits the data)
  • Session detail: "Temperatures"
  • Live: "Derate forecast — live"
• Left on auto-scale: Wi-Fi RSSI (negative dBm, so 0 is the top of its range) and SNR. Phase voltages and pilot already reach 0 in the data.

Risk

• Display only; no API or data change.
• Small changes take less of the chart's height. The heat-rise chart exists to catch a climb of a few degrees: on a 0-50 C axis a 3 C step is about 6% of the plot instead of about 15%. The drift verdict under the chart is unaffected.

Verification

• uv run pytest: 179 passed; node --check on app.js.
• Served this branch against a scratch copy of the production database (snapshot 2026-10-14) and read the rendered axes in Chrome:
  • heat rise per segment: 0, 10, 20, 30, 40, 50
  • heat rise vs ambient: 0 to 50 on y
  • session 101 Temperatures: 0, 25, 50, 75, 100
  • The live derate forecast only renders while charging, so it was checked by code reading only. It takes the same lineChart option as the other three.

Deploy: git pull on the mini-PC; static files are served with Cache-Control: no-cache, so no restart is needed.

🤖 Generated with Claude Code