Two fixes for the Grafana chart widget:
1. Invisible lines: the CHART_COLORS used 'hsl(var(--chart-1))' but the
CSS variable is named '--color-chart-1' and already contains a hex
color (#4f8cff). The hsl() wrapper produced invalid CSS, making
every stroke invisible. Fixed to var(--color-chart-1).
2. Multiple series collision: the backend labeled all Prometheus series
with the value field name (often just 'Value'), so multiple time
series collided on the same recharts dataKey and overwrote each
other. Now extracts meaningful labels from the Grafana frame metadata:
prefers displayName, then Prometheus metric labels (e.g.
'instance=server1:9100 mode=iowait'), then falls back to the field
name. Duplicate labels get a numeric suffix for uniqueness.
Multi-series queries now render correctly: each Prometheus time series
gets its own colored line with a unique label in the legend/tooltip.
280 backend tests pass (+1 labels test); 127 frontend tests pass; ruff/
eslint clean.
Developer
94bf830955