A dashboard canvas is CSS-scaled to fit its panel while uPlot maps the
pointer against its own unscaled plot width, so the cursor drifted further
right the further into a chart it went. A `cursor.move` refiner divides the
visual offset back into layout pixels; unscaled hosts get a no-op.
A querying chart's range picker moves onto the frame's title line through a
new `useHeaderSlot`, giving the plot back the row it spent. The editor's drag
handle is the header, so the picker is exempted from it.
Charts can be drawn as a monotone cubic spline — uPlot's own path builder,
monotone so a smoothed line never invents a reading between two real ones.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016ZeGnqVsf5VHQqvz4HdUhN
stroblmeandClaude Opus 5
680c6053b9