v1.42.0

Added

• Device health graphs — voltage, temperature, fan speed and more. Each device now keeps a history of its hardware sensors (/system/health): supply voltage, board and CPU temperature, fan RPM, PoE current/power — whatever your model exposes. They're shown as a chart card on the device page with a metric selector and 6h / 24h / 7d / 30d ranges, auto-scaled so small drifts are visible. Requested in Discussion #40 — handy for spotting a failing fan, an overheating switch or a sagging PSU without needing a separate SNMP monitoring system. Samples every 5 minutes, kept 90 days by default. The card appears only on devices that actually have sensors (so it won't show on CHR or sensor-less models), and it doesn't add a tab — it sits with the live-traffic graph above the existing tabs.
• SFP optical graphs — Rx/Tx power, temperature, voltage per fibre port. The other half of Discussion #40: when you open the traffic graph for an interface that has an SFP/SFP+ module, a new Traffic / Optical switch appears. Optical mode charts received and transmitted optical power (dBm), module temperature and supply voltage over 6h / 24h / 7d / 30d — so you can watch a fibre link degrade (dropping Rx power) or an optic overheat before it fails. Same 5-minute sampling, kept 90 days. No new tab — it lives right on the existing traffic card.